Re: Benefit of 2 GTX 280's over 1 GTX 280 with these monitors
Pretty sure the second GTX 280 would give you a significant increase in performance for the 2560 x 1900. If anything deserves two GTX 280's, it's definitely that res.
A second GTX 280 for 1920 x 1200, well, I think you'd be better off with two GTX 260's in terms of price/performance. A second 280 would probably give you a noticeable increase in FPS, not sure if it would be high enough to spend that money in my opinion.
EDIT: Wow, both i7s! Those should be some pretty bangin' machines.