The TR2-M12 is as quiet as you're likely to find. It's an all-copper
HSF with a really quiet 80mm fan that pushes 32.4CFM. Newegg and
other places carry it; Newegg has a large number of customer reviews
for that part. Sometimes its called the TR2-M12 SE. And sometimes
not. If you use Google, try both versions. It has another alias:
the Thermaltake A4012-02.