Its not as overwhelming as it looks. Im not going to get into detail (Zanthem did a good job of that), but that motherboard you have makes it REALLY easy to OC. I have same mb and cpu. I have it clocked to 3.4ghz on air (Artic Freezer Pro). A big factor is air flow in the case. If you have a good case w/ lots of room and air flow, you can get some very nice overclock w/o going to H2O. I also have my 8800gts 640, and ram oc'd, it took me about 4hrs (not counting the time to stress test).
Check out
www.extremeoverclocking.com