Well, it seems he wants the best and having 2 3870X2s is actually cheaper than buying ULTRAs in SLI, and will yield more performance and probably consume less power. The 3870x2 is available for around $450-500.
BTW what do u plan on doing with this thing?, i mean a terabyte is that necassesary. the only way i can think of filling up anything close to a terabyte is like 20+ games and a jillion songs.