3x Antminer OC 400Mhz
Chieftec Navitas 1250C
http://www.chieftec.eu/en/psus/navitas-serie/gpm-1250c.html
3x Cougar CF-V12HP fans powered str from Antminer second board fan connector.
http://www.newegg.com/Product/Product.aspx?Item=N82E16835553002
How much does that actually help with airflow and cooling? I am seriously considering this, but don't know if it actually helps or is just a bit gimmicky...
it definitely helps. However, there is a tradeoff between the extra fan cost ($15 for a good one with >70cfm) and how much more you will mine by overclocking an extra 5-10GH.