There a few nice ones we have dove; Edison Bridge, School Bus, and the Pegasus. All are about 30 to 45 miles off shore in 65 to 85 feet. There are no corals, but plenty of fish. You can go inside the Pegasus which is an 85 foot steel boat. I guessed on the length.
Go to www.EarthNC.com and Load the load http://earthnc.com/floridareefs into google Earth. It will show you all the permited reef sites in FL along with the Lat/Long and the compisition or what is there along with depth.
Also you might want to visit you're local dive shop and see if they have the book by Ned Deloach "Diving guide to Underwater Florida" it also has some information.
I used the information on Google Earth to Dive 1 mile Reef off of Anna Maria and the Lat/Long put me right on top of the reef.