Melanie,
Given 4 docs and 8 exam rooms, not including the front desk and back room folks that would need access, you should probably consider getting a beefier box for the server - more like a Dell PowerEdge 2900 with 2x quad core Xeon - you can get refurbished models off lease with 3 year warranty for about $2000 and these are much more fault tolerant and less likely to cause problems.
