cooling mono amps

I have two BATVK-55 mono block amps sitting in an Audiov Zirconia rack. They give off a lot of heat when the ac is not on. I read threads about pulling the air away from the tubes and have seen 5.25" fans on line, two configured in a 19" panel. I was wondering if one of those mounted at the back of the rack, one behind each mono block, will suffice? Should I include a thermostat? Is ther another quiet fan I should be looking at? I would appreciat your comments and suggestions. Thank you.