Physically the RAM should fit in the slots as the RAM slot spacing is industry standard. Asus mobos however tend to be RAM sensitive IME. You may want to e-mail Corsair Tech Support and see if the exact RAM part number you desire has been used in the exact mobo model - without issue.
As far as the O/S is concerned you'll need a 64-bit O/S to use more than ~3.5 GB. of RAM.