The K in 56K stands for the number 1024, a commonly used multiplier in the computer lingo. Just like the SLIP and asynchronous dial-up cases described above, leased lines require you to connect to an internet access provider. The big cost involved in using a leased line is the line itself. In the Champaign County area, Ameritech and GTE are two sources which you can contact for availability and pricing of leased lines. The cost of internet access itself also goes up.
PSI has very similar pricing.
It may seem strange, but this is the case. However, if you go to a leased line solution, you must pay for both the line and the internet access. Anixter is another good overall source for networking equipment and supplies, including wiring products. The router part of the link is important. However, if you're going to supply the equipment yourself, you need to study up on the issues of routers.