I'd recommend DDR3-1600. 1.5v.
The video card you chose is pretty weak for that computer. You'll need something more powerful if you plan to play newer games at 1080p.
The psu is major overkill. A 400w psu would be sufficient for that setup. If you go with a HD7850/70 or better I would recommend a 500w psu.
However at that price I'd probably stick with the 650w. Tigerdirect has a slightly better deal with rebate and free flash drivehttp://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2768070&CatId=1483