video card on my new mac

Hi

I'm about to buy a new mac
wiil certainlly be a MacPro / 2 x 2.8 quad-core Intel. With a lot of ram (between 8 / 16 Go)

I saw in the Apple store i can buy it with differents video cards. (hopefully).
Can anyone tell me what's the best for SL client ? I use the last version of SL release candidate.

4xATI Radeon HD 2600 XT 256MB GDDR3
NVIDIA GeForce 8800 GT 512MB GDDR3
or standard
ATI Radeon HD 2600 XT 256MB GDDR3

I don't know what are differencies betwween those hardwares...
(i'm not a specialist on video cards)

Oupsssss
I also need two monitors working on my card.
(24 inches laCie and 19 inches)...

Thanks for your help and advices
kisssesssss

not sure about SL specifically and if there are any problems with any specific cards.... but...

the 8800 is a much better performing card in theory, and can run 2 monitors fine. the 2600XTs are ok, but you only need 2, or 3 or 4 of them if you are driving a lot of monitors, basically each card can have two monitors. I dont see any reason you should spend money getting 4 of the 2600s in there when 3 are gong to be sitting around doing nothing. at best youll have one monitor on each card, and only 2 will be doing nothing.

The 8800 would be the way to go, just try to do some searching and see if there are any problems with 8800s people are experiencing. They are pretty new to OSX, and i know there were some strange issues with the 8600s when they first starts selling those. hopefully they have the bugs wored out for that family of GPUs, but you never know.

OK Missy... thanks for your answer...
I think i gonna use the 8800... after a few searchs

And thanks to correct me
i have'nt understood that x2, x3, etc...
was the number of cards...

I have a Mac Pro with the 8800 GT, it kicks ass. I've never managed to get it below 20 fps on full-detail (with lowered draw rate, I still don't see the benefit of more than 64m for the cost).