'Roids. To make yoru computer as strong as can be, you need to inject it with massive amounts of steroids. I'd recommend shooting it directly into the DIMMS, but others prefer to go through the back and actually start at the power supply.
For a server, video card doesn't matter. It's all about bandwidth of your internet connection. Aside from that, I think Ram is the most important (at least 1024mb), followed by cpu (at least 2ghz). As for a hard drive, get a SCSI.
That setup should run things just fine.
