Best radiator fans for Termaltake 2.0 performer?

I currently have the Thermaltake 2.0 Performer water cooler cooling an intel i7 3770k overclocked at a stable 4.8GHz. The temps are OK, however they could be better. While running prime95 the temps get to be around 80-85c. I currently am using the one stock fan that comes with the system and 1 bad exhaust fan behind the radiator (I don't even know the brand lol), but I can tell it does not move very much air.

Any recommendations as to which radiator fans I should get? I was looking at the DELTA fans, but I don't really want it to be unbearably loud.