Barebone Help

Have you looked into a build-to-order pc?

You are having trouble finding the E6600 because it was discontinued a while back and is now out of stock at most retailers. If you're dead set on an Intel rig I'd suggest looking at the E5200 or E7200 (as roadrunner suggested) or alternatively something in the E2xxx series.

At the price range you're looking at I would strongly suggest taking a look at AMD systems. You could buy a fast Athlon X2 and pair it with one of the cheaper 790GX motherboards and still have plenty of money left for a good power supply and a decent case. This would probably give you the best system to grow with as starting out with the better PSU would allow you to easily add a nice video card in the future.

The Intel systems will overclock better, but if that's not your primary interest then I feel that the AMD system might be the better option for your budget.

Case with a quality PSU $75
Mobo $59
DVD Burner $25
CPU $89
All in one card reader included with case
Assembly

Total $300

Add 2G ram for $40
Add 500G HDD $80
Add Vista Home Premium $100
Add ATI 4670 Video for $80 "better then the 8600GT"

$600 complete, with a three year warranty available, and lifetime support.

Pick and choose, through what you need/want.

That motherboard isn't the best, but it will support an 8600gt.

8 is DEFINATELY not stanard. Anything over 2 is useless.

Don't get the 8600gt though. For a little bit more, you can pick up a 9600gso. I think those can be found for about 80 bucks on newegg.com, should be a bit faster than the 8600. If you don't want to spend too much on video, or the 9600gt is pretty reasonable as well, and nearly as fast as the 8800gt.