Mannix Custom Builders is proud to serve clients on the East End, Suffolk County, Long Island and in New York City. HAMPTONS: Amagansett, Bridgehampton, East Hampton, Quogue, East Quogue, Hampton Bays, Montauk, Napeague, Noyac, North Sea, Sag Harbor, Sagaponack, Shelter Island, Southampton, Springs, Wainscott, Water Mill, Westhampton, Westhampton Beach. NORTH FORK: Calverton, Greenport, Mattituck, New Suffolk, Orient, Peconic, Riverhead, Southold. NEW YORK CITY: Manhattan.