Speaking of bridges, if you take the Mobile to Western
Florida route, there are three 50 foot bridges to contend with on the Intracoastal Waterway if you choose to use any of it between Mobile Bay and
Carrabelle. Between
Pensacola and Fort Walton there are 50 footers at Navarre and at Ft Walton. There is another 50 foot bridge just East of
Panama City.
It can be a nice sail of about 100 miles outside on the Gulf from Pensacola to Panama City which will bypass the first two bridges. You can stop at Destin which is about halfway, but you probably can't get onto Choctawhatchee Bay because of the bridge across Destin pass. This bridge is charted at 50 feet but it's notorious for clearing a bit less, especially in the summer. Destin Harbor itself is on the Gulf side of the bridge so you can get in there. Be careful, the pass shoals often although it was recently dredged.
To bypass the bridge East of Panama City, you can either go outside on the Gulf around Cape San Blas to the
West coast of Florida which will take about two to four days, or you can go outside to Port St. Joe (about 25 miles), then take the Intracoastal Waterway to Apalachicola and
Carrabelle. The crossing from Carrabelle to the
West coast of Florida is about 36 to 48 hours.
Both the Panhandle and the West Coast of Florida are excellent cruising areas offering beautiful protected, uncrowded
anchorages, relatively inexpensive
marinas (relative to South Florida and the Caribbean) and great sailing. One problem you may have is that the
weather in the Panhandle can be hit or miss from November to February. There are many cold, windy, wet days mixed in with some very nice days. It warms up somewhat South of Tampa.
You may be able to find some good information on your planned route (the US part at least) by googling "Cruising the Great Loop". A good bit of the Great Loop covers the route you are talking about especially the rivers, the Panhandle, and Western Florida.
You might also consider going to
Central America rather than the
Caribbean. I have never been, but I've heard good things about it and I'm sure some others will chime in with good information. Going to the
Caribbean will be against the prevailing winds; not so much with
Central America.
Whatever you choose to do, have a great trip!