You didn't come in here asking that question, but your asking the wrong question. What I tried to tell you is that it doesn't matter what motherboard you put two 8600GT's into, they still suck. With good/high settings, they will not allow you to play Crysis at 1680x1050 at 30+ FPS. It has NOTHING to do with the motherboard, it has everything to do with the low end 8600GT. Its been awhile since I've looked at 8600GT SLI scores, but the 9500GT is very similar.
http://www.tweaktown.com/reviews/1521/9/leadtek_winfast_geforce_px9500_gt/index.html
Lets pretend for just a second that you could actually get perfect doubling of the frame rates with SLI. In this case, that 9.11 would get doubled to 18.22, still to slow. Even if you game on a lower res monitor, 12.6 doubled is only 25.2, still sub 30+. Worse, you should know that SLI doesn't perfectly double your score, so you are looking at probably 13-15 at 16x12, and 16-19 for 1280x1024.
If you want to play Crysis at 30+, dump the low end SLI idea and just get a more powerful card. Seeing as you want to spend ~$200 on a new motherboard, spend it on the 4850. This will handle Crysis just fine.
Seeing as you are talking about your next build, you don't need to worry about getting the x48. The x2 doesn't need a CF motherboard. Any P35/45 will do fine. I personally wouldn't spend ~$200 on a motherboard if the new x58 series is coming. Upgrade options will be limited for such an expensive board.