Orlando is ~ 3 hrs from Ft. Myers 
Tampa BGT is ~ 2 hrs. 
 
Busch Gardens is a great park and if you like zoos, even better 
Montu, Kumba, Gwazi, Python and Scorpion. 
 
If at all possible, spend two days, one at BGT and one at Islands of Adventure. 
 
Driving time is only about 7 hours total, and it will be a great time that you'll never forget. 
 
Have a great time, what ever you decide.