SLI: GT or GTS?

I'm building a SLI gaming rig, but will only run one card for now. I'll be playing games on a 24" monitor with a native rez of 1920x1200. Just World of Warcraft for now, but probably more demanding games in the future.

Should I get an 8800GT or 8800GTS card?

I'm concerned if I only get 8800GT and one day get another for SLI, it may not be enough to run future higher demanding games, so two 8800GTS' would do better.

Or will it not make much of a difference?

two 8800 GTS will be better if you don't plan to buy 4000 series ATI or gt200 series nvidia

a gtx280 is supposedly going to be significantly more expensive than 2 8800 GTS 512s

2 8800 GTS 512 is about the same as a 9800 GX2 - except 100$ cheaper

I really think that the OP should wait at least and see what the GTX 260 is going to be like price/performance wise before making a purchase. But the GTX 280 is going to be much more expensive than SLI 8800 GTS or SLI 8800 GT

No one knows how exactly the GTX 260/280 performs and all of this benchmarks arent 100% accurate because the cards arent out yet
I say go for 2 8800GTS 512 if u can, they perform better also they can max out every game out there