I have dove most of the keys and personally I would probably forgo Key west unless you are there for the night life. Key Biscayne offers a nice wall drift dive with depths up to 100 ft. The middle keys are good to, Islemarada and Marathon. From them you can hit the three big wrecks in less time. The best diving in Florida I find actually in West Palm beach, short boat rides, deep water and great wrecks/reefs and tons of sea life. Just about any dive operation will give you the same service and prices, as they are very competive. Just depends on what you are looking for. Capt. Slates in the middle keys is very good and well known and they have been there for ever. They also have a little motel on site.