Alt Box Specs?

AMD Anthlon 64 2.2GHz Single Core AM2 CPU
Nvidia GeForce 7600GS 256MB PCI-E
1GB (2x512) DDR2 800 RAM
WD Caviar Blue 80 GB 7200rpm SATA HDD
BIOSTAR AM2 Geforce 6150/nForce 430 Micro ATX Mobo
Acer 17' LCD Monitor
Athena Power 400W PSU

Is this enough to run 4x alts, not sure what I will be trying to run as a main PC but with WinXP, 4 of these will run just under $2000 total from newegg. This isn't counting any KVM stuff, no input devices or monitor mounts yet, just trying to get an idea of what kind of specs and hardware I will need for running alt comps.