The motherboard and CPU you have chosen are going to allow for some serious overclocks. The RAM however will limit you to around 3.0ghz. If you were to get DDR2-800 RAM you should be able to hit at least 3.2 if not 3.5+
If you don't plan on doing any serious overclocking then the XMS should work for you enough.
The Video card is a pretty powerful card but i'm not too sold on their own brand of the card. If you could maybe find a premier company such as eVGA BFG or XFX that would be better.
The Case may give you heat problems as it only has 1 80mm side fan. I recommend at least one fan in the front and one in the back. Extras are nice though.
Your PSU is overkill. Look for a good 400-450 watt PSU. That should be all you would ever need.
E6300 w/ Arctic Freezer Pro 7 @ 3.6ghz 1.4Vcore
Antec 900 Case
EVGA 750i FTW Mobo
4x1GB of G.skill DDR2-800
2 8800GT in SLI
22" Samsung Syncmaster
1 250GB WD and 1 Seagate 7200.10 in RAID 0
Corsair 520HX 3DMark06 Score: 13900