>I saw 2gb on the server...

If the server does not have any other server software running (like SQL engines), and users are using only VFP, then 2 GB is good memory for 8 users. Even if they run VFP and Excel, it should be enough.

A quick estimation of memory would be:
128 MB for Windows 2003 Core
4 MB for each user session
Memory used by each application of each user: I estimate 30 MB for VFP + databases opened, and 20 MB for Excel (core and standard workseets).

8 users would be: 128 + (4 * 8) + (30 * 8) + (20 * 8) = 560 MB

And this is not completely accurate, as Terminal Server does not waste the same amount of memory when the same application is opened several times, ie if you open 8 sessions of Excel, it does not waste 20 * 8, it wastes less.