I would go with a Corsair PSU, I would go with the Phenom II X4 955 Black Edition, and I would get at least a 5770 (if you can afford 2x 5770, your benchmark will go even higher).
If you go with the Phenom II and get two 5770's, make sure your mobo will support it. For just an extra 100 or 150, you can probably get these parts and you'll be doing a lot better, IMO.
Edit: Looks like I might be late to the party, but this is a good resource: http://www.tomshardware.com/forum/forum-31-322.html
A lot of the build experts there recommend the Phenom X4 955 BE when you don't have the coin for an i7. Basically, if you give them a budget, they can recommend the best everything for what you're trying to do. Edited, Aug 10th 2010 11:26pm by Oenos
XI - Draiden 75DRG/75COR (Sylph, Retired 08)