Looks good, but I'd upgrade to 1 GB of PC3200 (same type, just two sticks). That RAM is perfect, but you'll want more for the newer games. Even 768 MB from 512 MB makes a BIG difference in some games, with 1 GB being the most you'll need for games.
Everything else looks good. NewEgg has a damn nice Sapphire Radeon 9800 Pro for cheap (it's like $225). Get that one...a 256 MB version won't improve the system much, if at all. You'll save the money, and then be able to get 1 GB of RAM instead of 512 MB.
The processor is DEFINITELY worth it. I've heard that the Athlon 64 3000+ is the best bang-for-your-buck in the 64 series, however. But if money isn't an issue, I'd go for the blazing 3200+. If you get it, it'll be one HELL of a system -- those games won't be a problem for it. Just another day at the job for a system like that.
-Lasereth