What do you have in mind for this system? Crossfiring and SLI'ing is a pain to say the least. There will be always be driver issues for a lot of games. A single 680 would be at least 3x times faster that those old 88's. I'd get:
Intel i7 3770 (non-K)
Corsair 8GB DDR3 1600MHz CAS 9
Asus 680 or 670 if you want to save cash
Given the age of your PSU, I'd also gate a Corsair TX 650 v2.