If you're willing to sacrifice 5 1/2" drive bays cramming this stuff in should be easy. Otherwise I'd recommend doing as you were going to do and drilling out the rivets that hold the lower-front drive cage in place, then placeing the psu there and mounting the radiator where the psu usually goes. Unorthodox? yes; will it work? absolutely. Then the pump can be attached to the ceiling of the case where you were originally planning on mounting the radiator, and this leaves space for a small res/flowmeter/insert-dodacky-here behind the psu on the bottom of the case. Te compriendes? Te gusta?