Actually nothing comes to mind that fits your specs on Key Largo. Maybe Anchorage. Dinner Key in Miami or Plantation in Islamorada would be two that bracket that. It is getting late in the season to nail down something halfway decent . What do you plan on doing with the boat while down there? Do you need easy access to airports, shopping, etc? Going to be away from the boat for extended periods? Budget? You'll save some money if you can sign a multi-month lease.
"There's the Right Way, the Wrong Way, and what some guy says he's gotten away with"