Well, for SLI you'll need a nForce motherboard. There's a rumor these aren't as overclockable as Intel P965 or 975X motherboards, which do not support SLI. They may
support CrossFire with a future upgrade (or even hack), but it's uncertain.
If you want SLI, the best choice is probably the Asus P5N32-SLI (nForce 590)
In my opinion SLI/CrossFire isn't worth it, and there's a stickied thread about the pros/cons somewhere in the forum so that you can make your own mind.
If you chose to not have SLI, then there's the DS3, as we had considered, or the P5W DH
, which has Intel 975X chipset, but it's more expensive. In my opinion, the P5W DH is the best Core 2 Duo board on the market. I read a review where they pushed a E6300 to 2.9Ghz on this board (that's 420Mhz FSB). No other board that I read about could do this.
EDIT: here's the review
I was talking about. Give it a look. They also use Corsair DDR2 memory, so good choice.