Is the 6950 a good upgrade from the 6850? Or should i crossfire? I heard 6850 crossfire is just as good as the 580. Also some good solid motherboards for crossfire? I've been mulling over this forever; and i'm starting to get a little disconcerted. I really don't know what to do.
I game a 1080p
You won't gain much by stepping up to the HD 6950 from an HD 6850. If you are not happy with the performance of the card, I would recommend you add another one for a nice performance bump or wait for the HD 7000 series.