I have used small case fans, cpu fans on aftermarket heatsinks, water cooling, bigger case fans, etc, etc. (Just spent over $150 on 2 heatsinks with 3 fans total, 1 is a spare) Quiet is best achieved with water cooling. The BEST and cheapest way to cool your box and not have those fans go out on you is to just open the side and put that sidecover away, then get a GOOD table fan and just blow into the side. End of problems. Yes, i know your girlfriend will not be impressed, but so what, just tell her you are about making money and care less how it looks.