Air Orlando are good to deal with. I've rented from them many times and will be again in a couple of weeks.
Flew to key west a few years ago from Kissimmee and routed via VORs PHK and DHP. We flew above Miami controlled airspace which stops at 7500 feet if my memory is correct. This was much easier than the east coast route when it comes to radio work, if not as pretty. We decended to 1500 feet once clear of Miami.
Our flight time was 3 hours 10 min. On my limit in an old 172 but effortless in a new one.
Remember to file a DVFR flight plan.