Alright, everything is looking good, except A FEW things where you're getting pretty much scammed into buying higher priced parts.
First off, we'll start with the processor. The E8600, which has 1333MHz FSB, 6MB L2 cache, and is based on the 45nm technology, runs around $269, which is what you have. It also runs at 3.33GHz. If you pick up the E8500, you're paying almost $100 bucks less, with all the SAME specs as the E8600, except it runs at 3.16GHz. So you're losing about 100MHz, which you will, for sure and guaranteed, NOT NOTICE as far as speed goes. Save yourself the money, buy the E8500. (I would even buy the E8400 myself, which is around $20 less than the E8500. Same stats, runs at 3.0GHz)
With the operating system, you don't need Windows Vista Ultimate. You'll do perfectly fine with Windows Vista Home Premium. So, here it is
retail, which I believe includes 32-bit and 64-bit, and also includes the license to where you can install it on more than one motherboard use. Or, you could save over $100 dollars and buy the
OEM copy, 64-bit would be the best as you have over the 4GB of RAM it can recognize (combined with you video card, you really have 5GB. Different RAM, but still counted as a total). The OEM only allows you to install it on ONE MOTHERBOARD COMPUTER. So once you have it installed with the P5Q board connected to the hard drive, Microsoft considers that that is it, and you are not allowed to install that copy of windows on any other computer, or even the same computer if you upgrade the motherboard in the future.
With the hard drive, you'll notice no performance gain in gaming with a 10,000 RPM drive. If you buy a 7,200RPM drive with a 32MB cache, you'll be getting just the same performance as the VelociRaptor. The VelociRaptop is a 2.5" drive, that is in a 3.5" enclosure. This allows the drive to experience less vibrations in its enclosure and also dissipate heat that it creates. But really, pick up the Western Digital Black drive with 32MB of cache. More space, less price, equal gaming performance.