I'd agree with Juiced about the Sonata III case and PSU combo. The PSU is very efficient and has plenty of power for any single GPU, since it has 34A on the combined 12V rails. If you wanted to get a different case than I'd suggest the one below. It's $75 - $35 MIR = $40!!! Can't beat this case at that price. Very roomy and cools quite well at this price. You just need to jump on it before 1/22, if you want to qualify for the MIR.
COOLER MASTER RC-690-KKN1-GP Mid Tower Case Retail
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?Product...
Then drop it this PSU and your set for this combo:
$75.50 - $10 MIR = $65.50!!
CORSAIR CMPSU-450VX 450W Active Power Supply Retail ***Free Shipping***
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?Product...
or if you still like the Antec Sonata III case/PSU combo, get it here for cheaper:
$110 shipped!!! this usually gets a MIR at times, so shop around, but this is the best priced shipped that I can find without a MIR.
ANTEC Sonata III Mini Case Retail
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?Product...
the one at Newegg has a $40 MIR, so it's final cost is $90, but you'll have to wait for the MIR to get to $90.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
I'm with the rest on the build, so get these to maximize your gaming.
Cpu - q6600 (if you OC later) or get the e6750 now and buy a Penryn Quad later when the prices come down.
Mobo - Gigabyte DS3L is good and solid board. If you need RAID than the DS3R would be the one to get. Other mobo's to consider are: Abit IP35-e or Asus P5K-se (both equivalent to DS3L). If you need RAID support the other alternatives are: Abit IP35 and the Asus P5k. All are solid and reliable mobo's. They each have their different options, so please check them out and see which one has all of the options that you require. They will all support Penryn chips when they come out (from what I've read).
GPU - 8800gts 512mb is probably the best GPU to get right now at a decent price ~$320ish. Then the 8800gt or 3870 from AMD would be the next step down. Those 3 selections would be the ones to consider at this point in time. There will be newer ones coming, but if your buying soon, I'd consider any one of them.
DDR2 - I'd get the 800mHz CAS 4 memory at this time, because its cheap and can OC well, when you get to that point. Get 2x1 gig's for XP or 2x2 gig's for Vista. I'd use Crucial/Corsair/Patriot/G.Skill/Kingston as one of the manufacturers of choice. I prefer Crucial Ballistix, but any of the CAS 4 memory would be good (4-4-4-12 timings to be exact for the 2x1 sets).
DVD burner - Get a "retail" version, so you don't have to buy the burning software seperately. The cost is usually only about $3-5 more to have the retail version.
OS - I'd personally go with XP Home/Pro instead of Vista, but I'm not the one buying. Vista will eventually be the way to go, but I'm not quite ready to jump on it, too many issues especially if your going to run older programs on your computer.