I agree with what Dash says, and to a certain extent with what Steve Wiggans says too! Myself, have a Carrier 38YZA heat pump and a VS fancoil, I can vouch for how well this system removes humidity. I live in south eastern Ontario Canada, and we only get hot humid weather in late may until early september. Yet I went for the variable speed airhandler for reasons of comfort. It also increase the HSPF of the heat pump when in heating mode too! So I benefit in both modes of the heat pump. Of course, I have the Carrier Thermidistat which controls the VS handler. Nevertheless, if I were you living in Florida, I would go with the variable speed air handler and the thermidistat control, you will be amazed at how well it works and how little it has to run to keep your indoor air dry and cool.
Steve's comments make a lot of sense too. Quite a bit about what he refers to is in the quality of instalation. So it pays to get the right contractor, no easy task as far as I'm concerned. Good luck, and I hope this helps