I never recommend multi gpu set ups. Get the fastest single gpu you can afford.
I know its never better, but I spent a large ammount of money more than half a year ago, to find out that it couldn't run BF3 on Ultra. Now I OC'ed it to 1100\1400, and it runs it on around 42FPS but its just not.. Enough.
Buying a brand new GPU is just bad for me, I don't have a job currently, and the crossfire idea sounded good but I guess its not :\
Thanks anyways guys <3