Jim,
Aquaponics systems will accept a wide variety of fish species depending on your goals. Fish such as ornamentals, Koi, gold fish, catfish, blue gill, etc. can be used but tilapia are usually the choice as they are the most tolerant of water quality fluctuations.
There are restrictions governing the species of tilapia used in Florida which you can easily clarify by contacting Joseph Clayton of the DACS Division of Aquaculture. Joseph can be contacted at joseph.clayton@freshfromflorida.com  or you may phone him at (863) 297 - 3985. 
You can also contact Richard Tyson.
Dr. Tyson is an excellent source of aquaponic information and can be contacted
by phone at (407) 254 - 9200 or by e-mail at rvt@ufl.edu   

Feel free to contact me at carlosvm@ufl.edu or phone me at (813) 671- 5230.