I never said CF was weak? I said a single card was weak. If you bought a single 7850 now and then CF'd THAT a few months down the line, you'd be getting EVEN MORE performance along with a good single card set up too.
Clearly you have already decided what you want to do so why even bother asking.
Personally on your *what seem's to be tight budget* - id be scrapping the SSD, buying a cheaper motherboard, getting a better PSU, and throwing a little more cash at the GPU, and getting 1600MHz RAM.