edit: I see you've already got your card. But I'll leave my previous comment.
Why not get the 460 GTX 1gb instead of 768? I remember seeing performance benchmarks saying this helped in certain cases. Particularly if you're doing a 1 gpu solution. I got mine for 180 with MIR about a month ago. There were some better deals on black friday, but its too late now.
The 460 gtx's overclock extremelely well too. So make sure you do that. I believe in benchmarking an overclocked 460gtx can match or beat a 470gtx (much more expensive card).
I upgraded from 2 8800 gt sli's (I did this so I could sell the cards and the upgrade not costing a lot, and enable sli in the future) to 1 460gtx and with it overclocked it does a little better...







