I go to the keys almost every year, sometimes twice a year and have done so for the last 15 years. Islamorada has the most options for lodging and is where the most guides are based out of, but there are plenty of options for both everywhere between key largo and key west. Personally i usually stay in islamorada but the last few years have stayed at the courtyard marriott in marathon which is a very nice courtyard. I have also camped at long key state park a bunch which is a great place to camp with a wadeable flat that used to often have bonefish in the mornings on the right tide.
I'm going to disagree with the last post. There are guides in the keys who will take you fly fishing but have never caught a bonefish or tarpon on a fly. Do you really want to pay $700-$800 plus tip for a guy that has never done what you are trying to do? You really should look for a fly fishing guide.
The bonefishing around islamorada is improving over where it was a few years ago, but it is still a tough go. The time of year you are going can be particularly tough as any type of cold weather will result in no bonefish on the flats. Honestly, that is pretty much the worst time of year to go if bonefish are your target. Personally if you are dead set on that timeframe i would look to the everglades (thats where most guides will probably push you unless they don't want to make the run) or look more towards the lower keys/key west. The everglades will be redfish, snook ect rather than bones though. IF you happen to get a few days of warm weather and no wind in february, tarpon can show up in the backcountry around islamorada.
I don't have a recommendation for a guide. My longtime guide retired at the end of 2018. i have a few days booked with randy stallings this may for tarpon. Based on phone conversations he seems very honest and upfront but I have yet to fish with him. i have never fished with any of the guides out of florida keys outfitters but if you can't get a good recommendation i would feel safe getting a guide from them. Regardless they are probably worth a call just to get a feel for what the fishing will be like the months you are going.