It has been quite some time since I've built a desktop and I've got a student loan of sorts coming in a few days for the purposes of putting together a new computer (I'm a computer aided design major as well as a FPS player).
So here is the products I've chosen so far, just would like some people with more knowledge on the subject than I to take a gander and make sure I didn't foul anything up too badly.
RAM: Corsair Dominator Series TWIN2X2048-8500C5D 2GB Kit DDR2-1066 (x2)
Hard Drive: Seagate / Barracuda 7200.10 / 500GB / 7200 / 16MB / Serial ATA-300 (x2 RAID of some sort)
Video Card: EVGA GeForce 8800 GTX GDDR3 / SLI Ready / PCI Express / Dual DVI / HDTV / Video Card (x1 for now, perhaps a second later)
Had a hard time finding a computer case that wasn't massive or ugly or a pile of crap but this is what i'm thinking at the moment: COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case with whatever 1000w bundled coolermaster PSU from newegg
one suggestion.. I work with AutoCAD 2008 primarily for my job. AutoCAD 2008 is mulithreaded, so I would suggest going with the Q6600 over the E6850. The Q6600 will be able to use all 4 cores.
Also like you I'm a FPS gamer.. The newer FPS games like Crysis will take advantage of the Q6600.