Its a real pain been boating here for years and the only place I know is Sanibel Harbour Yacht Club not sure if there are and slips available but you can give them a call.

No experience with storage, but we used their boat ramp for a bunch of 33 & 37 Active Thunders a few years back for the Thunder Run gathering.
Nice facility, but a little hard to navigate the area with a truck and trailer.
Boat Storage - Cape Harbour Marina

Sweet Water Landings Fort Myers just built new rack and storage

Salty Sam's Marina and Moss Marina both in Fort Myers Beach. Both are very close to the Gulf. I'm not sure of availability.

Fish tale on the south end of fort Myers beach has rack. 5 minutes to st Carlos pass