As you can see on the chart the 8600 just does not compare. They are meant for video playback and stuff and not gaming. Here:
I know it seems hard and other cards seem enticing with their low cost but in the long run you are better off with the 8800GTS 320MB. In fact they say the best card for the money (cost over FPS, Frames Per Second) is in fact the 8800GTX, but that is a crap load of money.
PS: your rig is starting to look awesome.
Edited by jackflash1991, 19 August 2007 - 10:34 PM.