Help Me Decide!

Im in the process of building a new PC and I had originally choice to buy 2 EVGA nivida 7600 gt for SLI. This is my first SLI, Dual core CPU blah blah blah system to build. Well talking to a friend of mine that build his system a few months ago told me that certain games including CSS and apps such as adobe photoshop and after effect dont use SLI technology and only uses 1 card.

My question is to all you gurus that really do know more than I about the issues.

First is it true? What have you all heard or experienced?

Second: For now Im sticking with Windows XP so not really worrying about the Direct X 10 games coming out and other issues with Vista. Should I stick with buying the 7600 GT's or buy 1 8600 GT and not worry about the whole SLI for know. The buy another 8600 GT when Nvidia works the whole driver issue out.

Thanks in advance
BDX

OK, good enough. Well after reading reviews the nvidia 8600 did not out perform the 7600 GT that much. Or not enough to justify spending the extra money. That is why I choose the 7600 GT's. Which card would you all recommend? Im not spending 500-800 dollar on a video card. I dont need it for that price. This is a link to the card with its specs here it is

http://www.newegg.com/Product/Prod [...] 6814130017

I play a few games but mostly graphic and web design apps like adobe, corel, and the like.

If I choose to buy the Nvidia 8600 or 8800 which are Direct X 10 cards. Is there any problems running Direct X 9 games? Do you have to use Vista?