DFI boards are fun if you want to spend a lot of time in the bios. . . (I don't find that fun, but some people do I guess).
I've had 3 DFI boards in the past and 2 of them have failed (all nForce 4 chips).
If you plan on going SLI, get the x48 board, otherwise, get the P45 board.
My sig obviously shows which one I'd get.