unless you're desperate for the Crysis epeen, you can build a Core2Quad system and gtx 260/216 for a fraction the price. That'll run everything but Crysis on max on a 22" screen, and it'll do the same for any games out in the next 9 months from what i've seen of the release lists.
My advice - wait. Grab yourself a 4850 or the like to tide you over for another year, then go i7. Even a 4850 on an old Athlon X2 will eat up most anything at 22" res.
If you must have a new system and must spend all that money, i'd recommend you just build a C2Q system like i mentioned, and invest the rest of the cash in peripherals and a quality desk / chair if you don't already have them. A 24" screen and good keyboard/mouse/mousemat/headphones will do far more for your gaming enjoyment than a few extra fps.