^+1 you will need an LGA1156 CPU to go with that board. If you want to stick with the i7 you will need to select a proper LGA1366 board
5850 crossfire would be faster. That board has two slots between the two PCI-E 16x slots so your cards will have a little breathing room. Seems as though they overheat if there is only one space between them since the first one can't get enough air.
1. You need a 1366 socket board for that CPU and RAM. perhaps consider one of the new Asus boards w/ USB3 and / or SAS
2. Dominator RAM is way overpriced in recent weeks. Comparable OCZ is $119
3. The 1 TB WD is older 333 GB platter design. Get a Spinpoint F3 or Seagate 7200.12 500 GB per platter design....the WD 2 TB model has 500GB platters
4. That PSU is twice the wattage it needs to be and quality wise, aint so hot.
5. The CPU HS is ok, but not among the very to performers....personally I prefer the Megahalems both for ease of install and better performance
6. I'd grab this over the one you selected http://www.newegg.com/Product/Product.aspx?Item=N82E168...
But Antec 1200 w/ CP-850 is probably the best bang for buck combo out there right now.
7. 1600x900 is weak resolution. Suggest these and they're HD and cheaper http://www.newegg.com/Product/Productcompare.aspx?Submi...
8. GPU is ez....pick how much ya wanna spend and then read this:
First as others have said your motherboard and cpu are wrong. You have an 1156 (P55) motherboard an 1366 socket cpu which needs X58 motherboards. Generally for 200 you can grab one of the lower end motherboards for that socket though. Second your monitor is only 20" yet you want 2 5850s (which is better in then 2 gtx 285s). My single 4890 is pushing a 26" monitor just fine. My advice to you is to get 1 5870 and then spend the 200 saved from buying 2 5850s compared to a 5870 and get yourself a nice 24" monitor.