Hunter, your wattage calculations are way off
You can calculate with 200W per CPU at 4,5Ghz (these Hexas don't use more power than Bloomfields, actually it's less at identical clocks/volts even with early A0 sample CPUs)
Maybe 300W for OCed Fermi cards (conservatively), 100W for the mobo with its Dual NF200's and another 100W or so for HDDs, pumps, fans etc.
In all, you should be fine with a single, good 1500W PSU.

Cooling-wise I'd say dual loop, quad rad for the GPUs and quad rad for the CPUs/mobo is more than enough.

@Mick64: Incredibly awesome cases, I want one
But please, include that "XL-ATX" support for the DP classified - no cases out for that board really