If you want quite Venice beach and Sarasota they have all inclusive quite resorts on the beaches and they are gorgeous. Keys and Miami are nice but they are also crowded and loud and not guaranteed to have any available all inclusive resorts. You could also stay in Ft. Lauderdale its close to Miami and you can take a boat to the Bahamas for a day for around 99 dollars ship leaves at 730 and arrive on the island at 12 or 1 includes breakfast has casino and drinks and entertainment. Then the ship leaves at 6pm includes dinner.
Key West is a drunk fest overrun by cruise tourists. Miami Beach is for couples. You can also go north to Ft Lauderdale which is also nice. The upper keys are very nice and are not as crowded. You may also want to check out Delray Beach.
I suggest St. Augustine. Stay in a bed and breakfast. Most of them have rooms that have whirlpools in the rooms. Or try the Casa Monica hotel. St. Augustine is really a quaint city, and 1 of the most romantic cities in Florida.
congratulations, and Kokomo by the keys is good
totally in miami beach if your a young couple its fun
Go to the keys and hit one of their all inclusive resorts. They rock.