CORSAIR CMPSU-850TX 850W ATX12V 2.2 / EPS12V 2.91 SLI Ready
CrossFire Ready Active PFC Power Supply $129.99
The power supply might be a little too powerful but incase i want to add a second video
card, i thought i would leave the option open.....
Western Digital Caviar Black WD1001FALS 1TB 7200 RPM 32MB
Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive $87.99
COOLER MASTER HAF 932 RC-932-KKN1-GP Black Steel ATX Full Tower Computer Case $135.98
I love it how people say "simple gaming build", or "Price is my biggest issue" and then proceed to list some of the most expensive parts. Changes I would make for a "simple" build.
Dump the i7 for an i5. (or an AM3 build) You don't need a $285 mobo for a gaming build. And don't worry about the i5 running two cards at 8x each. First, you said your leaving that option open so it might never come into play. And second, the difference between 16x and 8x is very small. Even if you go that route your frame rates will be single digit % smaller. (think 2-5% if I remember correctly.) This should free up a lot of $$$.
Next thing to do is change the video card. With your new found $$$ you should be able to get either the 6970 or the GTX570. Both are around $100 more then the card you listed. If your just looking to save money I suggest you at least look at the 6950. One of AMDs newest video cards, it competes very well with the GTX470. It is a bit more, but better in most respects. (and most games.)
Cases are a subjective thing, but I don't like spending $130+ on a case. More so when that $$$ could be better spent on faster GPUs, CPUs, etc. If that NZXT case that Bat linked is the one I'm thinking of its a good case. I'm almost tempted to upgrade my case due to my harddrives and I'm considering that one. The Haf 932 is a great case. But your money is probably better spent elsewhere.
If you drop down to a P55 board and the 750, you should have enough money for the 6970/GTX570. Or you could keep the GTX470 (or get the 6950) and pop in an SSD for better load times. Or just keep the savings and buy some 30/36 packs. Not sure what you're wanting to do.