I'll give this a shot.
First, being in the Orlando area, you will be closest to freshwater, maybe even across the street in a pond by wherever you are staying. They hold bass and bluegill and are lots of fun on 5wt or 6wt. I would use sinking flies as with the cold( at least it's cold to us down here,LOL) the fish will usually be in deeper water. You can get by with a floating line, which is what I use all year round. You will be close to Lakes Toho, both East and West, Kissimmee and not too far from a lot of lakes in the immediate area. The only catch is you will most likely need a boat to fish these lakes.
As far as saltwater goes, there is always the Mosquito Lagoon with Redfish and Trout, and the Indian and Banana rivers are both wadeable in many spots. The trout have been in the light colored sand holes in the grass later in the day trying to warm up after the cold nights, but the reds aren't as affected by the cold as the trout, and they have been biting small Seaducers, but they are also on the spooky side, but by wading, you can get pretty close. I use a kayak in the areas I fish here, more to get where I want to go fish, than to fish out of. Make sure you have a good pair of polarized sunglasses to see the fish, and I usually go later in the day when the sun is up so I can see the fish better.
Also, stop by Orlando Outfitters, great folks that can give you the latest info on where you can go in the Orlando area.
Hope this helps!