8800 GTX good enough for powering dual 30 inch monitors?

I read the sticky on multi-GPUs but was still unsure of my situation.

I already own a 680i EVGA motherboard with one BFG 8800GTX card (not overclocked). I currently have a 24" and 20" monitor hooked up to it. I'm want to ditch these smaller monitors and upgrade to 2 30" LCD monitors (I was also considering 4 24" monitors but was thinking that 2 30" monitors would be best and obviate the need for monitor tree stand).

My usage for machine is 90% trading/quant research. I need more screen real-estate for my various trading charts - sometimes upwards of 30 charts running in parallel plus a dozen or more apps as well with all their windows.

10% of time I like to unwind and play a good game so will make use of 3D horsepower at times.

My question is this: will one 8800 GTX be sufficient horsepower for 2 30 inch monitors running side by side? Does it make sense to buy another 8800 GTX and put it in SLI mode to help power these 2 30 inch monitors, assuming I can still use 2 30 inch monitors in dual mode while in SLI? Or will SLI only benefit me 10% of time when I want to play 3D intensive games (particularly if games of the future can make use of dual monitors)?

Thanks for any feedback and/or advice..

JD