Look at my signature. I also begun with with the same Swiftech kit you have. The MCR-220 couldn't deal with my Q6600 B3 heat dissipation, even at 3.2GHz. It was too hot and I had my fans at 12v to deal with it
I added a PA120.3 (adding a MCR-320 QP on your loop will breake your flow, especially if you're planning to add the NB and SB to the loop, as the MCR-320 is more restrictive than the PA120.3) and I could get my B3 to the same OC in my signature, with all the 5 fans at 5v. I now got a Q6600 G0 that needs much less vcore than my B3, and it is even better now
Here, you can find the PA120.3 in stock, the best radiator for LPDC ever made.
http://www.xtreme-cooling.ch/catalog...oducts_id=1611
As you're mounting the circuit, better install it while your PC is open. But of course, you know you'll suerely have to mod your case to fit a triple rad