Q:

GAE - Different Project for different clients or Different version of the same application for different clients? 

I am working on a system on GAE that includes app server, Datastore, a mobile app and a web client. 
My each customer will need to have a customized (separate) app server, datastore, mobile app and a web client.  I am not able to find any information on how I should design my system:
[Option A]:-Separate project for each customer, hence app server and datastore will be available exclusively for that customer.  In the sense, do I need to clone my base project for each of my customers and then customize to have separate datastore and appservers ? 
OR
[Option B]:-Same project with different versions of application for each customer.  In this case, can I have individual (exclusive) data store and app server for each customer?  In the sense, I want a separate datastore and app server for each customers.  I am not sure if I can take advantage of using different datastore buckets for different customers for my requirement. 

I could not find any reference link addressing my problem. 
Any help will greatly be appreciated. 
Thanks in advance! 

A:

You should consider App Engine's native support of multitenancy.  If this is not good enough for your requirements, then you will have to create a separate project for each customer.  The Datastore for a single project is shared across all versions, so you will not be able to segment it (unless you are ok using namespaces as described in the linked doc).  
I would also recommend making sure that you actually need to have separate applications running for each customer.  Unless you sign up for a premier account, you have a limited number of projects that you can create.  Besides that, it will most likely make management of those apps much more difficult for you.