Well, money is a consideration as usual. I'm on a $1500 budget. The good news is the processor doesn't have to fit in that budget. It's free from work. The bad news is I need EVERYTHING. Case, monitor, keyboard, drives....all in that $1500.
With the games I run (various flight sims) I leaning toward 780i with a single 8800GTS card for now and getting a second card later. That way I can spend more now for a decent monitor and other parts.