We have a SuperArm lift installed on our motorhome which works very well for me. I can't give you a recommendation for a Florida installer but try calling some of the companies who install lifts in vans. They may be able to help. My lift was installed in Pittsburgh by a van lift installer. I've seen motorhomes with traditional lifts installed which seems to more complicated because the RV has to be modified so that the lift can slide under the chassis.
Any lift installation will involve some cutting into the side of the RV to install a wider door.
This Florida company installs SuperArm lifts -
http://www.wheelsunlimited.com/index.html Here's another type of lift which is unusual because it mounts on the outside of the RV -
http://www.rvwheelchairliftsoftexas.com/ Good luck! Please feel free to ask questions.