Jay69
Rackable Systems Servers (bunch on ebay(Rackable Systems), yahoo is upgrading, so their from yahoo data centers)
The 2.66ghz Daul Xeon's are rockets.
SME is 32bit but runs real good on the 64bit Xeon's
There's some Racks already setup w/70 servers in a rack for $11K if that's within your budget.
Maybe a GB Nic Card.
Most certainly GB network for 20 users CAD.
The Rackables, some have (2)-Intel GB nic's
HTH