P67 crossfire bench

Has anyone seen benchmarks for p67 boards in crossfire?

I've already purchases my i5 2500k (awesome price at microcenter) now im trying to figure out the rest of my build. I play at 1920x1080 so I'd like to get 2 6970's in crossfire to max out everything in the graphics department. I just want to make sure I'm getting my moneys worth by going crossfire. Would it be worth investing in one of the motherboards that have the nforce 200 chips to get better bandwidth? Any ideas would be deeply appreciated and welcome.

Thanks

Nate