Video card doesn't matter for running dedicated servers. CPU speed isn't terribly important either, provided it's somewhat modern.
What you'd want is RAM and lots of it, and a fast disk system. 1 GB is a decent amount for running one or two dedicated game servers. For disk I'd look at the WD 8MB Cache drives at minimum, if not something nicer. (Maybe SATA and some Raptors)
SMP is not completely necessary in this situation but the more you're having this server do, the more SMP will make a difference.
(e.g. if you're serving -one- dedicated game server and doing NOTHING else, skip it. If you're serving two or more dedicated games, serving files on your home network, running http/ftp servers.... then get a dual processor machine. DC projects [Seti/Folding] would be a reason to get a dual processor machine as well)