Dont worry about raid, it takes around a good 15 seconds to array your drives. I suggest eVGA ,BFG, or Ledteck 6800's. These are better cards to OC. Also for RAM, i suggest OCZ Platinum Rev2, or G Skill LA's. Those are the most fit for OC. The eVGA and BFG card wont cost anymore. The RAM i suggested will be a little more, but from the type of system you got going, i dont think money is a issue. Even if you cant pull that RAM, i would drop SLI all togather. Just for the fact that the new generation video cards are coming out in a few months. Anyone that has dual 6800's will be reluctant to upgrade. At this moment, going SLI with the video cards available would be a little to deep. Just for the fact the new generations are coming out. Its something to think about though.