I'm also in Florida and my house regularly hits 83 with the A/C constantly running. It's a big, older house with tons of windows so it has a hard time keeping cool.
Before we purchased our 7.0 cu ft GE freezer for fermenting, we used a swamp cooler like what has been mentioned (a plastic storage tub filled with water), and I was able to keep our beers around ~66 during the initial days. I'd generally put in around 4 frozen 2-liter bottles of water before work, check it when I got home and either leave it or add more frozen water bottles and then add some more before we went to bed. It's a royal PITA but it is feasible.
I adore my converted freezer. It hold 2 6.5 gallon vessels on the bottom and a 2.5 gallon fermenter on the bump.