Ok so I am back to square 1 with what to pick... your board has a different layout but space wise its = to 2 PCI slots in between them (like mine) so the bridge works fine.. so... now ....
4850x2
4890 (and later Cross Fire with 4870 or 4890)
..other?..
Since the GTX really won't show much improvement and all, I'll stick with the first brand I ever got.
Pretty sure the 4890 in crossfire with another 4890 later in life would blast most anything I do, it'd be like a 4890x2 after all (which they will probably have on the market by the time I buy a second card) and 4890 might be able to Cross Fire up to the next series... so I guess getting a 4890 would be the way to go right now?