Most the the places I know of are in the Abacos, not
Exumas. Depends on size of your
boat but Browns
Boat Yard in
Nassau can do it.
Marsh Harbor Marina, Man of War Cay, the marina in Black Sound in Green Turtle Cay have all done jobs for friends with good result. All these in Abacos. All of these can do many catamarans.
George