I'd look to Key Largo... Why??
-Shallow reef, many sites are around 40'. They also have deeper dives, and some great wrecks.
-Short boat rides to the reef, maybe 20-25 minute (it always seems very short, so I may be slightly off).
-Insurance reasons, you're still in the USA, should it be needed.
-Easy to get to, fly into Ft. Lauderdale, rent a car and before you know it you're in the Keys.
-Many great operators (from what I've read), although all my experience is limited to Rainbow Reef.
-Native English speaking instructors are abundant.
As far as specific operators, like I said I've only dove in Key Largo with Rainbow Reef. On my last trip down I reached out to a few other shops, but things didn't work out with them. With Rainbow, they use mostly (exclusively??) big boats, Newton 42' boats. These are often called 'cattle boats', I've never been with them in the high season, so I enjoy the 'big boat' without being on board with too many people.
Some other knocks on them, they're big, and the crank out instructors, so there are a lot of newer/ younger people working there. I would avoid the newer instructors. I'm sure they smart, and caring, and everything else, but I'd request one of the more experienced instructors. Some of them include, Jardin, Phil, Yariem AKA Aqua (he's Cuban, but speaks VERY good English), Corey, Gia.
At the very least I'd give RR a call, or shoot them an e-mail. If you do go with them, try to get one of the instructors listed above.