Blech.  If you weren't in FL, I'd suggest evap cooling.  You don't really have another option in FL besides AC, I'd imagine.  

I'm cooling:
4  x 5990s
38 x 6970s
8  x 6870s
4  x 5870s
all in one room.  Roughly 12,000 watts (just a little under).  Everything is being cooled buy a single window mounted evap cooler (in an adjacent room) that draws 285 watts at full fan/pump speed (and I shut it off at night).  Because an evaporative cooler is being used, I'm able to keep temperature *and* humidity in check.  If you want to run a large Bitcoin farm, a desert climate is definitely the way to go.