As far as Florida goes, Alafia river state park, FL has camping and is the second best bike park in Florida, although with some of the improvements in the last year or so, some people are saying it is as good as Santos. When were you planning the trip?
Also, it would be bit a longer trip, but Markham Park down by Miami is very good, we did a week down there for spring break a couple years ago. It is probably third best in the state, and there are three other trail systems near there for day trips, Virgina Key, Amelia Earhart, and Oleta River. The places with camping in Broward county are C.B. Smith, Easterlin, Markham, Quiet Waters, and T.Y.? Quite Waters does NOT have full hookups.