Corsair PSU; the Xclio GoodPower 500W or GreatPower 550W would be better for the price that Corsair 450W is at. Better performance as well.
EVGA 8800GTS 640MB; not needed. Get the 320MB, 1% performance increase isn't worth the extra $40-$50. With that extra money, you can spend it on something else.
Crucial Ballistix Tracer; no need for the LED's. Just get the regular ones. Crucial Ballistix DDR2 800.
Everything else looks fine, but for your Q6600; you should get the Tuniq Tower 120 along with a tube of AS5, MX-1, or MX-2.