I am more of a fan of Jacksonville for fishing purposes, general area, and cost of living. My whole family is from there and loves it. Miami is a bit too big for me. My Aunt is a Realtor -Top Producer and lives in the Ortega part of town if you would like her opinion/contact information let me know.
In terms of the 31 Contender, there are many homes off the St. John's River that have deep water access and docks. Went to Miami for my Bachelor Party and it was a blast for fishing, just pressured and a major metropolitan city. However, it's only a 6 hour drive from Jacksonville if I remember correctly. Fishing in Jacksonville is pretty darn good, Mayport Inlet is awesome, offshore is pretty good, there inshore is loaded with the usual species. Tarpon bite is good. Ponte Vedra is the best area for fishing purposes - direct access to the Ocean.
In terms of schools, check out St. Mark's in Ortega or Bolles in Jacksonville. Episcopal I have been told is great also. Hope this helps. Ask the guys at Black Fly Outfitters about fishing or Strike-Zone.