Not that great. First, the WD HDD is going to be slow. Get the Samsung Spinpoint F3 500 GB For $55 or the 1 TB for $75. It'll be faster and cheaper.
Second, that PSU isn't that great. OCZ's units are really cheap, but not high quality. Check out some 650W units from Corsair, SeaSonic, XFX, Silverstone and Antec to ensure quality. For example, here's a XFX 650W and XFX 5770 for $150 after rebates, which is a great deal.
Third, that RAM is really slow. I'd recommend looking for at least 1333 mhz sticks with at most CAS Latency 7. If you want to overclock, get 1600 mhz CAS Latency 7 sticks. G.Skill's Eco series is excellent in the 1600 mhz/CL 7 range.
Fourth, I'd look at a board with 8x/8x Crossfire. The ASRock 870 Extreme 3 is cheap at $100, and packed with features. It also constantly wins awards and recommendations.
Finally, I wouldn't get a monitor with a resolution under 1920x1080. A lower resolution monitor won't leave you any where to go in the future. Here's one that's pretty cheap: Asus 23" 1080p. There might be cheaper ones though.
EDIT: I should add that if these changes push the build out of budget, you could drop the CPU to an X3 445. Then pick up a cheap aftermarket cooler (Coolermaster's Hyper 212 Plus or Scythe's Mugen 2 Rev. B are excellent) later and unlock/overclock it.
To start, SATA III means absolutely nothing to standard drives. They simply don't have the speed to get above SATA II. SATA III starts becoming a factor with SSDs, but the technology simply isn't mature enough to make a significant difference yet. Give it a couple of years, and there won't be a point to getting a new SATA II drive.
On to the heart of the matter. There are more important specs that aren't quoted in most listings for HDDs. The number one factor in HDD speed is the platter size, or the amount of data stored on a single mechanical disk, with larger being faster, quieter and cooler running. The F3 has the largest platters available right now (500 GB).
I know some of the newer Caviar Blacks have the same platter size as the F3, but I'm unable to find specifically what the Caviar Blue's have. I highly doubt they'll be faster than WD's top of the line parts though, so I'll use the Blacks as a comparision, given the Blue's an undue advantage.
The new SATA III Caviar Blacks (the 500 GB platter versions) are just barely faster than the older (by 6 months) F3s, despite being a good $10-15 more expensive and touting SATA III support. The difference is so small, it's not even noticeable. Given how close the two drives are in terms of performance, the Caviar Black is never recommended. Why spend the extra for no real performance gain.
The Black line is WD's high performance line, and the Blue is WD's value line. The Black is surely faster than the Blue (or else there's no point to the distinction), which means AT BEST the Blue is equivalent to the F3. At a higher price, you'd be paying more to get AT MOST the same performance. I can't see the logic in that.
How big of a difference will the cache difference make? Also for the memory I found http://www.newegg.com/Product/Product.aspx?Item=N82E168... I know the Lancety is 9 still but is it decent memory? Or was the corsair better? I was also wondering if maybe I should go with a lower graphics card prehaps. I was conidering the xfx psu 5770 combo deal that Mad suggested.