i am currently running a Phenom 955 with this cooler http://www.newegg.com/Product/Produc...82E16835185142
and the fan I have hooked up to motherboard. When im not gaming all my case fans are barely spinning and inaudible and the CPU fan doesn't even kick in. I have used this cooler in both a cramped mAtx and a mid tower Atx and either way it is amazingly awesome.
Side not I have built 2 more Pc's with this processor http://www.newegg.com/Product/Produc...82E16819103846
and unlocked it to 4 cores. Being the C3 revision it has a little bit better thermal properties and cools just that much better than my 955. I have read though that not everyone gets the other 2 cores unlocked so it is a gamble.
In the end get fans under 1600rpm and use a fan controller or get 800 - 1200rpm fans
I just noticed the person above me is using the Mugen 2 also same processor too!