Port of the Isles Gun Club is located between Naples and Everglades City on US 41 (Tamiami Trail). They shoot Trap and Skeet. There is a club over near Homestead that I'm told shoots Olympic Skeet. There are a few other clubs in the Ft. Myers area but I would have to make calls to locate them.
As far as Gun Rooms, Dewings is located at West Palm Beach which makes it a day trip. On North up the east coast to Vero Beach is duPont/Krieghoffs new store. But back in Ft. Myers the only Dealer of Fine Guns I am aware of is Dave Riffle.
http://daverifflegunsales.com/Your family member is welcomed to give me a call (438-7403) when he is in this area. If he cares to hunt I can show him some decent WMA ground that might make him happy. There are also some pay hunts nearby.
John E.