The Mattress Capital | Mattress Stores in Wilmington, Jacksonville, Southport, Shallotte, Myrtle Beach, and North Myrtle Beach Mattress stores in Wilmington, Porter's Neck, Jacksonville, Southport, Shallotte, Myrtle Beach, North Myrtle Beach. Buy Postur-Pedic, Stearns & Foster, Sealy, MLILY, and Englander.