no offense, but you fail. in that scenario, the video card couldn't even render more than a few FPS and you'de be entirely limited by that. I'm not going to bother to point out your folly, I advise you learn more about computer and application architecture before posting much more advice.
I might just go with the 8800GTS 320MB, And Maybe another GIG of RAM.. Its not that I don't want the 8800GTS, it's just.. I ain't getting Vista at all, period. Not until X-mas maybe.. Vista is ---- (and lets not talk about that here guys).