If you're looking for compatibility information for specific heatsinks from thermalright I highly suggest looking at their website.
http://www.thermalright.com/new_a_pa...ck-120-mcl.htm
I also agree with magictorch that it would be not in your best interest to air cool the system given its capabilities with a more advanced cooling system, you would not be getting the best value out of the motherboard if you want to cool the system by air alone.