A lot of unnecessary spending, going on here.
Get the WD 750GB hard drives instead. They're as fast as the Raptors, and they cost around the same price.
Get Crucial Ballistix DDR2-800. You can't beat it's price, for the amount of performance, it gives.
You don't need a sound card. Onboard is good enough. You just need good speakers.
Get either the Gigabyte P35-DS3R, or the ASUS P5K Deluxe, as they are well suited for the Q6600.
64-bit OS, is not needed. So ditch the 4GB of RAM, as that is not needed as well, unless you're into CAD or any software, of that type.
The Tuniq is great for the Q6600.