<PAGE>   1
                                                                   Exhibit 10.20

                                   [FORM OF]
                       RESTRICTED STOCK PURCHASE AGREEMENT


         RESTRICTED STOCK PURCHASE AGREEMENT (this "Agreement"), dated as of
April 26, 1999 ("Effective Date"), between CGA Group, Ltd., a Bermuda
corporation ("Seller"), and [____________] ("Purchaser").

         WHEREAS, the Board of Directors of Seller has directed that Seller
offer to sell to Purchaser an aggregate of [_______] shares of its Series C
Convertible Cumulative Voting Preference Shares, par value $.01 per share (the
"Series C Preferred Stock"), on the terms and subject to the conditions set
forth herein;

         WHEREAS, Purchaser is employed by Seller or a Subsidiary of Seller and
desires to purchase the shares of Series C Preferred Stock so offered on the
terms and subject to the conditions set forth herein; and

         WHEREAS, concurrently herewith, Purchaser has executed and delivered a
promissory note to seller dated as of the date hereof.

         NOW, THEREFORE, to implement the foregoing and in consideration of the
mutual agreements contained herein, the parties hereto agree as follows:

         SECTION 1.  PURCHASE OF SERIES C PREFERRED STOCK

               (a) Purchase and Sale of Shares. Subject to the terms set
forth in this Agreement, and in reliance upon the representations, warranties
and agreements of Purchaser contained herein, Seller hereby agrees to sell to
Purchaser, and Purchaser agrees to purchase, a total of [___________] shares of
Series C Preferred Stock (the "Purchased Shares"), at a price of $1.20 per
share, which represents an aggregate purchase price of $_______ (the "Purchase
Price"), with such transaction to occur on the Purchase Date (as defined below).

               (b) Purchase Loan. On the Purchase Date (as defined below),
Seller will make a loan to Purchaser (the "Loan") in the amount of $ _______ for
the purpose of financing a portion of the aggregate Purchase Price payable by
Purchaser (maximum 90% of Purchase Price). The Loan will be evidenced by a
promissory note to be executed and delivered by Purchaser (a "Note")
substantially in the form of EXHIBIT A hereto.

               (c) Closing of the Purchase and Sale; Payment for Shares. The
closing of the transactions contemplated hereby shall take place at the offices
of Seller on April 26, 1999, or at such time, date and place as Seller and
Purchaser shall mutually agree (the "Purchase Date"). At the closing, Purchaser
shall pay the Purchase Price to Seller, by executing and delivering the Note and
by payment of $_________ in cash or by cash equivalent acceptable to the
Company, and as promptly as reasonably practicable thereafter, Seller shall
deliver to Purchaser a duly executed certificate representing the Purchased
Shares.

               (d) Voting and Dividend Rights. Purchaser will have all voting
rights with respect to the Purchased Shares. Cash dividends and distributions
payable with respect to the


<PAGE>   2

Purchased Shares shall be the property of the Purchaser. Any other interests of
Purchaser with respect to the Purchased Shares shall be determined as otherwise
set forth in this Agreement, including the vesting provisions of Section 2
below.

         SECTION 2.  VESTING

               (a) Vesting and Transfer Restrictions. The Purchased Shares
will be subject to the vesting and transfer restrictions to the extent set forth
in this Section 2 (such Purchased Shares are sometimes referred to herein as
"Unvested Shares" during the period that such restrictions apply and as "Vested
Shares" after such restrictions have expired). Until the lapsing of the vesting
restrictions set forth in this Section 2, Unvested Shares may not be sold,
transferred, pledged, encumbered or otherwise disposed of by Purchaser (except
by will or by the laws of descent and distribution) and shall be subject to the
Call Option set forth in Section 3 hereof.

               (b) Vesting Events. The Purchased Shares shall become Vested
Shares (i) immediately on the Purchase Date for the number of shares represented
by the cash payment made by the Purchaser and (ii) on each date that the
Purchaser makes a principal payment on the Note, for the number of shares
represented on such repayment (based on the Purchase Price per share)
Notwithstanding the foregoing, the Purchased Shares that are Unvested Shares
shall become earlier vested upon an Involuntary Termination or a Change in
Control, each as defined below in this Section 2.

               (c) Termination of Employment.

                    (i)  Involuntary Termination.  In the event of
termination of employment of Purchaser prior to vesting of any Purchased Shares
either (a) by Seller without Cause (as defined below) or (b) upon the Disability
(as defined below) or death of Purchaser (each such event, an "Involuntary
Termination"), the vesting and transfer restrictions of this Section 2 on any
Unvested Shares shall immediately lapse, and such shares shall become Vested
Shares.

                         (1)  For purposes hereof, the term "Cause" shall mean
(i) the willful failure by the Purchaser to substantially perform his or her
duties as an employee of the Seller (other than due to death or Disability)
after reasonable notice to the Purchaser of such failure, (ii) the Purchaser's
engaging in serious misconduct that is injurious to the Seller in any way,
including, without limitation, by way of damage to its business reputation or
standing, or (iii) the Purchaser having been convicted of, or entered a plea of
nolo contendere to, a crime that constitutes a felony or involving moral
turpitude. Notwithstanding the foregoing, in the event a Purchaser is party to
an employment (or similar) agreement with the Company or any Subsidiary (as
defined below) that defines the term "cause," such definition shall apply for
purpose of this Agreement.

                         (2) For purposes hereof, the term "Disability" shall
mean the total and permanent disability of the Purchaser, as determined by the
Board of Directors ("Board") in its sole discretion.

                    (ii)  Voluntary Termination.  In the event of any
termination of the employment of Purchaser prior to vesting of any Purchased
Shares for any reason other than an Involuntary Termination (each such event, a
"Voluntary Termination"), Seller shall have a Call

                                       2
<PAGE>   3
Option under Section 3 on the Unvested Shares of Purchaser, and may accelerate
the principal and interest due under the Note (in accordance with its terms).

                         (3) For purposes hereof, "Subsidiary" shall mean
Commercial Guaranty Assurance, Ltd. and CGA Investment Management, Inc.

          (d) Change in Control. In the event that a Change in Control
(as defined below) of Seller occurs prior to vesting of any Purchased Shares,
the vesting and transfer restrictions of this Section 2 will automatically lapse
with respect to all Unvested Shares. For purposes hereof, a "Change in Control"
shall be deemed to have occurred upon the occurrence of one of the following
events:

                    (i)  The consummation of the acquisition by any person (as
such term is defined in Section 13(d) or 14(d) of the Securities Exchange Act
of 1934 (the "Exchange Act")) of beneficial ownership (within the meaning of
Rule 13d-3 promulgated under the Exchange Act) of more than fifty percent (50%)
of the combined voting power of the then outstanding voting securities of the
Seller;

                    (ii)  The cessation, for any reason, by the individuals
who, as of the Closing Date, are members of the Board to constitute a majority
of such Board, unless the designation of any new individual as a director is
pursuant to the right to designate a director granted to certain members under
the By-laws of Seller, and such new director shall be considered as a member of
such Board; or

                    (iii)  Approval by stockholders of: (1) a merger or
consolidation if the stockholders of the Seller immediately before such merger
or consolidation do not, as a result of such merger or consolidation, own,
directly or indirectly, more than fifty percent (50%) of the combined voting
power of the then outstanding voting securities of the entity resulting from
such merger or consolidation; (2) an agreement for the sale or other disposition
of all or substantially all of the assets of Seller other than an agreement for
such sale or disposition to a corporation which, immediately prior to such sale
or disposition, is owned directly or indirectly by the stockholders of Seller in
materially the same proportion as their ownership of stock immediately prior to
such sale or disposition.

     For purposes hereof, the term "Change in Control" shall not mean the
following:

               (a)  An initial public offering of the capital stock of the
Company resulting in net proceeds to the Company of at least $50 million;

               (b)  A merger of the Company with, or acquisition of the Company
by, any other entity if such merger or acquisition, as applicable, is approved
by the Board or any other recapitalization or change in capital structure,
whether public or private, of the Company, in each case, after which, and for a
period of one year following any such transaction, the Purchaser holds the same
position as set forth in his employment agreement with the Company (or, in the
case of a Purchaser who is not employed pursuant to an employment agreement, has
the same position, duties and responsibilities as existed prior to any such
transaction), has the same chain of command, reports to the same individual or
individuals, and suffers no material change in his employment.

                                       3
<PAGE>   4
     Notwithstanding anything to the contrary contained above, a Change in
Control shall not be deemed to occur solely because more than fifty percent
(50%) of the combined voting power of the then outstanding securities is, or all
or substantially all of the assets of the Company are, acquired by: (i) a
trustee or other fiduciary holding securities under one or more employee benefit
plans maintained for employees of the Company; or (ii) any corporation which,
immediately prior to such acquisition, is owned directly or indirectly by the
stockholders of the Company in materially the same proportion as their ownership
of stock immediately prior to such acquisition.

         SECTION 3.  CALL OPTION ON UNVESTED SHARES

               (a) Voluntary Termination. If Purchaser shall no longer be
employed by Seller by reason of a Voluntary Termination, then Seller, by written
notice (the "Call Notice") to Purchaser (or his legal representative), shall
have the right and option (the "Call Option"), but not the obligation, to
purchase all or any portion of the Purchased Shares that remain Unvested Shares,
at the repurchase price set forth in Section 3(b) hereof, for a period of ninety
(90) days following the effective date of such termination. If Seller exercises
such right, Purchaser shall have the obligation to sell such Purchased Shares
specified in the Call Notice, at the Repurchase Price (as set forth below) of
such repurchased shares. Notwithstanding anything herein to the contrary, Seller
may assign its rights under this Section 3 to any of its Subsidiaries.

               (b) Repurchase Price. For purposes of this Section 3, Seller
may repurchase Unvested Shares at a per share repurchase price equal to the sum
of (A) 1.20 per share, plus (B) any accrued but unpaid interest on the Note
through the closing of the Call Option, calculated on a per share basis (subject
to any applicable tax withholding requirements in the event such repurchase
price exceeds the fair market value of the shares on the closing of the Call
Option). Payment of the repurchase price may be made, in the discretion of
Seller, in cash, cash equivalent, by offset of the corresponding principal
amount due under the Note upon a Voluntary Termination, or by a combination of
the foregoing forms of payment. Any amount of appreciation equal to the excess
of fair market value at such time and the Purchaser's original purchase price
shall be forfeited by Purchaser to Seller, and Purchaser shall have no rights
whatsoever with respect thereto.

               (c) Closing. The closing of any purchase under this Section 3
shall be held at the principal offices of Seller on the 30th day after the date
of the Call Notice, or at such other time and place as Seller and Purchaser
agree upon. At such closing, Purchaser shall deliver or cause the delivery of
certificates representing the Purchased Shares to be sold, duly endorsed for
transfer and accompanied by all requisite stock transfer taxes, and, except as
specifically provided herein, such Purchased Shares shall be free and clear of
any liens, claims, options, charges, encumbrances or rights of others arising
through the action or inaction of Purchaser, and Purchaser shall so represent
and warrant, and further represent and warrant that he is the beneficial owner
of such Purchased Shares. Seller shall deliver at the closing payment for such
Purchased Shares by check.

         SECTION 4.  SHAREHOLDERS AGREEMENT

               As a condition of this Agreement and the Purchaser's right to
acquire the Purchased Shares hereunder, the Purchaser shall be required to
execute and agree to be bound by the terms and conditions of the CGA Group, Ltd.
Shareholders Agreement dated as of June 12, 1997, as amended and restated as of
March 31, 1999, as such Shareholders Agreement applies to holders of Series C

                                       4
<PAGE>   5
Preferred Stock, and the Company agrees that Purchaser shall be afforded the
rights and privileges set forth in such Shareholders Agreement with respect to
the Purchased Shares upon their conversion into Company common stock.

         SECTION 5.  ISSUANCE OF SHARES; RIGHTS AS A STOCKHOLDER

               (a)  Stock Certificates.  Stock certificates representing the
Purchased Shares shall be registered in the name of Purchaser.

               (b)  Legends. Certificates representing Purchased Shares to
which the provisions of this Agreement apply shall bear the following legends:

                    THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
                    REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR
                    UNDER ANY STATE SECURITIES LAWS, AND MAY NOT BE SOLD OR
                    TRANSFERRED EXCEPT IN COMPLIANCE WITH SAID ACT AND THE RULES
                    AND REGULATIONS THEREUNDER AND APPLICABLE STATE SECURITIES
                    LAWS.

                    THIS CERTIFICATE AND THE SHARES OF STOCK AND ALL RIGHTS
                    HEREBY REPRESENTED ARE SUBJECT TO THE TERMS, CONDITIONS AND
                    RESTRICTIONS SET FORTH IN THE RESTRICTED STOCK PURCHASE
                    AGREEMENT DATED APRIL 26, 1999 AND THE SHAREHOLDERS
                    AGREEMENT DATED JUNE 12, 1997, AS AMENDED AND RESTATED AS OF
                    MARCH 31, 1999, AND MAY NOT BE SOLD OR TRANSFERRED EXCEPT IN
                    ACCORDANCE WITH THE TERMS AND CONDITIONS OF SUCH AGREEMENTS,
                    COPIES OF WHICH ARE ON FILE AT THE OFFICES OF CGA GROUP,
                    LTD.

               (c)  Rights as a Stockholder. Except as otherwise provided in
this Agreement, Purchaser shall have the same rights and privileges as any other
stockholder holding the same class of stock, including, without limitation, the
right to vote the Purchased Shares and to receive distributions and dividends on
such Purchased Shares. Purchaser's rights as a shareholder are subject to the
making of provision for the payment or withholding of any taxes to be withheld
pursuant to any applicable law in respect of the receipt or lapse of forfeiture
with respect to such shares.

         SECTION 6.  REPRESENTATIONS AND WARRANTIES

               (a)  Representations and Warranties of Seller.  Seller represents
and warrants to Purchaser that:

                                       5
<PAGE>   6
                    (i)   Seller is a corporation duly organized, validly
existing and in good standing under the laws of Bermuda, and has the requisite
corporate power and authority to execute and deliver this Agreement and to
perform its obligations hereunder.

                    (ii)  The execution, delivery and performance of this
Agreement, and the delivery of the Purchased Shares have been duly authorized by
all necessary corporate action on the part of Seller.

                    (iii) This Agreement has been duly executed and delivered by
Seller and constitutes the legal, valid and binding obligations of Seller,
enforceable against Seller in accordance with its terms, except as enforcement
thereof may be limited by bankruptcy, insolvency or other similar laws affecting
the enforcement of creditors of creditors rights in general or general
principles of equity.

               (b)  Representations and Warranties of Purchaser.  Purchaser
represents and warrants to Seller that:

                    (i)   Purchaser is acquiring the Purchased Shares for his or
her own account and not with a view to distributing or reselling the Purchased
Shares in any transaction that would be in violation of any federal or state
securities laws;

                    (ii)  Purchaser (a) is familiar with the business of Seller,
(b) has had an opportunity to discuss with representatives of Seller the
condition of and prospects for the continued operation of Seller and such other
matters as he deemed appropriate in considering whether to acquire the Purchased
Shares and (c) has been provided access to all available information about
Seller requested by him;

                    (iii) Purchaser understands that the Purchased Shares
have not been registered under the Act, or registered or qualified under the
securities laws of any state, and that she may not sell or otherwise transfer
the Purchased Shares unless the Purchased Shares are subsequently registered
under the Act and registered or qualified under applicable state securities
laws, or unless an exemption is available that permits such sale or transfer
without such registration and qualification;

                    (iv)  Purchaser's intention is not to transfer, sell or
otherwise dispose of any Purchased Shares prior to the registration thereof
other than through a transaction that would not require registration of such
shares under the Act; and

                    (v)   this Agreement has been duly executed and delivered by
Purchaser and constitutes the legal, valid and binding obligation of Purchaser,
enforceable against Purchaser in accordance with its terms, except as
enforcement thereof may be limited by bankruptcy, insolvency or other similar
laws affecting the enforcement of creditors' rights in general or general
principles of equity.

         SECTION 7.  MISCELLANEOUS

               (a)  Withholding of Taxes; Notice of 83(b) Election. Seller
shall have the right to require Purchaser to pay to Seller the amount of any
taxes that are required to be withheld with

                                       6
<PAGE>   7
respect to Purchaser's Purchased Shares, including any such taxes required to be
withheld in connection with (i) any dividend or distribution in respect of the
Purchased Shares, (ii) any conversion of Unvested Shares to Vested Shares, or
(iii) any sale of Purchased Shares. Purchaser shall promptly notify Seller if
Purchaser makes an election under section 83(b) of the Internal Revenue Code.

               (b)  Governing Law. This Agreement and the rights and
obligations of the parties hereto shall be governed by, and construed and
enforced in accordance with, the laws of the State of New York, without giving
effect to the conflicts of laws principles thereof.

               (c)  Specific Performance. The parties hereto acknowledge that
there will be no adequate remedy at law for a violation of any of the provisions
of this Agreement and that, in addition to any other remedies that may be
available, all of the provisions of this Agreement shall be specifically
enforceable in accordance with their respective terms.

               (d)  Severability. The invalidity or unenforceability of any
provision of this Agreement in any jurisdiction shall not affect the validity or
enforceability of the remainder of this Agreement in that jurisdiction or the
validity or enforceability of this Agreement, including that provision, in any
other jurisdiction.

               (e)  Notice. All notices and other communications hereunder
shall be in writing and, unless otherwise provided herein, shall be deemed to
have been given when received by the party to whom such notice is to be given at
its address set forth below, or such other address for the party as shall be
specified by notice given pursuant hereto:

         If to Seller:

                           CGA Group, Ltd.
                           Craig Appin House
                           8 Wesley Street
                           Hamilton HM 11 Bermuda
                           Attn:  James Reinhart

         If to Purchaser:

                           -------------------------
                           -------------------------
                           -------------------------

               (f)  Binding Effect. This Agreement shall inure to the benefit
of and shall be binding upon the parties hereto and their respective heirs,
legal representatives, successors and assigns.

               (g)  Amendment and Modification. This Agreement may be amended,
modified or supplemented only by written agreement of the party against whom
enforcement of such amendment, modification or supplement is sought.

                                       7
<PAGE>   8
               (h)  Headings; Execution in Counterparts. The headings and
captions contained herein are for convenience only and shall not control or
affect the meaning or construction of any provision hereof. This Agreement may
be executed in any number of counterparts, each of which shall be deemed to be
an original and all of which together shall constitute one and the same
instrument.

               (i)  No Rights to Employment. Nothing in this Agreement shall
constitute an offer of employment to Purchaser or be construed to require Seller
to continue Purchaser in the employ of Seller for any stated period of time.

               (j)  Entire Agreement. This Agreement and the Note constitute
the entire agreement, and supersedes all prior agreements and understandings,
oral and written, between the parties hereto with respect to the subject matter
hereof.

               IN WITNESS WHEREOF, Purchaser and Seller have executed this
Restricted Stock Award Agreement as of the date first above written.


                                   CGA GROUP, LTD.



                                   By:__________________________________________
                                      Name:
                                      Title:



                                   PURCHASER

                                   _____________________________________________


                                       8
<PAGE>   9
                                                                       EXHIBIT A
                                                                TO EXHIBIT 10.20
                                   [FORM OF]
                                 PROMISSORY NOTE



$________________                                            April 26, 1999


         FOR VALUE RECEIVED, the undersigned, __________________, an individual
residing at __________________, ("Maker"), hereby promises to pay to the order
of CGA Group, Ltd., a company with limited liability formed under the laws of
Bermuda (together with its successors and permitted assigns, the "Holder"), at
the Holder's address at Craig Appin House, 8 Wesley Street, Hamilton HM 11,
Bermuda, or at such other place as Holder may designate from time to time, the
principal sum of _________________ ($_________) in legal and lawful money of the
United States of America, together with accrued interest thereon as set forth in
Section 1 hereof, which interest shall accrue on the outstanding principal from
and including the date hereof, but excluding the date on which the principal and
all accrued interest are paid in full. The principal of this Note, together with
all accrued interest thereon, shall be due and payable in three equal
installments on April 26, 2000, April 26, 2001 and April 26, 2002, respectively
(or, if any such day is not a business day in each of New York, New York and
Hamilton, Bermuda, then on the next succeeding business day) ("Installment
Dates").

         This Note is issued in connection with the CGA Group, Ltd. Restricted
Stock Purchase Agreement dated as of April 26, 1999 between Maker and Holder
(the "Agreement") .

         Section 1.  Interest.  This Note shall accrue interest at the rate of
7% per annum.  Interest shall be payable on each Installment Date.

         Section 2.  Prepayments.  Maker may, at his option, prepay the
principal amount of this Note, and all accrued interest thereon, at any time and
from time to time, in whole or in part and without penalty.

         Section 3.  Acceleration.  The Holder will have the right to accelerate
the principal and interest due under this Note if any of the following events
(such event, an "Event of Default") occurs:

               (a)  During the period that any Purchased Shares remain Unvested
Shares under the Agreement, a termination of the employment of Maker occurs by
reason of a Voluntary Termination (as defined in the Agreement), effective
ninety (90) days after the effective date of such termination, or such earlier
or later date that is the closing date of the Holder's Call Option under the
Agreement, as to the Unvested Shares repurchased under the Call Option;

               (b)  Maker shall fail to pay any principal or interest amount due
under this Note on any Installment Date on or prior to such Installment Date;

                                       1
<PAGE>   10
               (c)  Maker shall fail to perform, observe or comply with any
other covenant, agreement, or condition contained in this Note and such failure
continues for a period of ten (10) days following written notice to Maker from
Holder of the continuation of such failure; or

               (d)  Maker (i) shall generally not, or be unable to, or shall
admit in writing his inability to, pay his debts as such debts become due; (ii)
shall make an assignment for the benefit of creditors, petition or apply to any
tribunal for the appointment of a custodian, receiver, or trustee for himself or
a substantial part of his assets; (iii) shall commence any proceeding under any
bankruptcy, reorganization, arrangement or readjustment of debt law or statute
of any jurisdiction, whether now or hereafter in effect; (iv) shall have had any
such petition or application filed or any such proceeding shall have been
commenced, against him, in which an adjudication or appointment is made or order
for relief is entered, or which petition, application or proceeding remains
undismissed or unstayed for a period of thirty (30) days or more; (v) shall be
the subject of any proceeding under which his assets may be subject to seizure,
forfeiture or divestiture; (vi) by any act or omission shall indicate his
consent to, approval of or acquiescence in any such petition, application or
proceeding or order for relief or the appointment of a custodian, receiver or
trustee for all or any substantial part of his property; or (vii) shall suffer
any such custodianship, receivership, or trusteeship to continue undischarged
for a period of thirty (30) days or more.

         Upon the existence of an Event of Default, Holder may (i) declare this
Note outstanding, all interest thereon, and all other amounts payable at any
time or from time to time under this Note to be forthwith due and payable,
whereupon the Note, all such interest, and all such amounts due at any time and
from time to time under this Note shall become and be forthwith due and payable,
without presentment, demand, protest, or further notice of any kind, all of
which are hereby expressly waived by Maker; and/or (ii) exercise any rights and
remedies provided by law.

         Section 4.  Collection Costs and Expenses. If there is an Event of
Default, Maker shall pay all costs and expenses incurred by Holder, including
reasonable attorneys' fees and expenses, in connection with the enforcement and
collection of this Note.

         Section 5.  Governing Law.  This Note shall be governed by and
construed in accordance with the laws of the State of New York (without giving
effect to its conflict of law principles).

         Section 6.  Waiver and Amendment. Maker hereby waives presentment,
demand for payments, notice of dishonor, protest and notice of protest and any
and all other notices or demands in connection with this Note. No delay or
omission on the part of Holder in exercising any right hereunder shall operate
as a waiver of such right or of any other right under this Note. A waiver on one
occasion shall not be construed as a bar to or waiver of any such right and/or
remedy on any future occasion. Any provision of this Note may be amended upon
the express written agreement thereto of Maker and Holder at the time of such
amendment.

         Section 7.  Headings; Construction. The headings of the sections of
this Note are inserted for convenience only and shall not be deemed to
constitute a part hereof; words used herein of any gender shall be construed to
include any other gender where appropriate, and

                                       2
<PAGE>   11
words used herein that are either singular or plural shall be construed to
include the other where appropriate.

         Section 8.  Notices. Any notice or other communication permitted or
required to be given hereunder to the Holder shall be given to the Holder in
accordance with the Agreement. Any notice or other communication permitted or
required to be given hereunder to the Maker shall be given to the Maker at the
registered offices of CGA Group, Ltd. as set forth in the Agreement, or to such
other address as given to the Holder by the Maker in writing and agreed to by
the Maker.

         Section 9.  Lost Note. Upon receipt by Maker of evidence satisfactory
to it of the loss, theft, destruction or mutilation of this Note, and (in the
case of loss, theft or destruction) of indemnity satisfactory to it, and upon
reimbursement to Maker of all reasonable expenses incidental thereto, and upon
surrender and cancellation of such Note, if mutilated, Maker will deliver in
lieu of such Note a new note for the unpaid principal amount thereof and
carrying the same rights to interest on the unpaid principal.

         Section 10. Severability. Any provision of this Note which is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof, and any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render
unenforceable such provision in any other jurisdiction.

         IN WITNESS WHEREOF, the undersigned has executed this Note on the date
first above written.



                                          ______________________________
                                          [Name]

                                       3
<PAGE>   12
                                                                      EXHIBIT B
                                                               TO EXHIBIT 10.20
CGA GROUP, LTD.
Employee Stock Purchase Plan Participants
Closed April 26, 1999





<TABLE>
<CAPTION>
                                  Total              Total             Down               Loan
                                 Shares              Cost             Payment            Amount
                                 ------              ----             -------            ------
<S>    <C>         <C>           <C>          <C>              <C>              <C>
 1     Aseron      Ross           15,000.00        18,000.00        1,800.00          16,200.00
 2     Avidan      Martin         50,000.00        60,000.00        6,000.00          54,000.00
 3     Blacker     Kem            41,667.00        50,000.40        5,000.04          45,000.36
 4     Borg        Joshua         20,000.00        24,000.00        2,400.00          21,600.00
 5     Bourdeau    Isabelle       45,000.00        54,000.00        5,400.00          48,600.00
 6     Coon        Andy           25,000.00        30,000.00        3,000.00          27,000.00
 7     Coyle       James          35,000.00        42,000.00        4,200.00          37,800.00
 8     Egler       Gerri          20,000.00        24,000.00        2,400.00          21,600.00
 9     Faber       Carol          20,000.00        24,000.00        2,400.00          21,600.00
10     Fishbone    Scott          30,000.00        36,000.00        3,600.00          32,400.00
11     Lang        Yan-Meng        5,000.00         6,000.00        6,000.00               -
12     Liabotis    Elizabeth      15,000.00        18,000.00        1,800.00          16,200.00
13     Manion      Peter           8,500.00        10,200.00        1,020.00           9,180.00
14     McGovern    Geraldine      10,000.00        12,000.00        1,200.00          10,800.00
15     Miran       Michael       100,000.00       120,000.00       12,000.00         108,000.00
16     Parsons     Landon         83,334.00       100,000.80       10,000.08          90,000.72
17     Price       Richard       308,316.00       369,979.20       36,997.92         332,981.28
18     Pridgen     Tracy          25,000.00        30,000.00        3,000.00          27,000.00
19     Riordan     Brian          15,000.00        18,000.00        1,800.00          16,200.00
20     Steffelin   Edward         41,666.00        49,999.20        4,999.92          44,999.28
21     Stuhlemmer  Eric           15,000.00        18,000.00        1,800.00          16,200.00
22     Wasterlain  Jean-Michel    40,000.00        48,000.00        4,800.00          43,200.00
23     Yung        Ron             5,000.00   $     6,000.00          600.00           5,400.00
                                 ----------   --------------    ------------      -------------
                   Totals        973,483.00   $ 1,168,179.60     $122,217.96      $1,045,961.64
                                 ==========   ==============    ============      =============
</TABLE>