I think I'm gonna go for the BIG GUN and get the 14 inch Can Max Fan 1823 CFM (Really 1700 CFM).  However, it is quieter than all 10 inch fans yet has the same CFM if not more that most 12 inch fans have.  It also uses less amps than most 12 inch.  Since it has larger blades, it does not require as many RPM's to move the same amount of air as a 12 inch.  This in turn makes it quieter and more energy efficient [ranges from 213 to 230 watts.

So again, quieter than most 10 inch fans with same CFM or more than most 12 inch fans.

You have to watch this dude getting blown around with this thing on youtube and also SEE THE SIZE OF THIS THING next to him.

http://www.youtube.com/watch?v=4DxbWXo4dF4

I will sell the 8 inch hyper fan on eBay.  Someone is going to get a good deal on it.  Usually hydroponic growers buy these things.