The Mizell family (left) Beverly, center, Milton, Right,. Cheryl, and front center, Jeanette Mizell. The Mizells own a little record shop at an indoor flea market in Liberty City. "Mizell Records is a big voice in Miami when it comes to rhythm and blues," said Novice Johnson, Florida promotions manager for MCA Records, which handles performers such as Patti Labelle and Gladys Knight. "What they do is amazing." The Mizells, Johnson said, not only sell a large volume of records and tapes for a small outfit, but they also avidly promote local talent. "We listen when they tell us what's selling and what's not," said Johnson, who works from Pompano Beach. "I think they move more product than any other independent record shop in Florida." Mizell Records, at the east end of Flea Market USA, 3015 NW 79th St., sells about 250 albums and 200 cassettes each week. They also sell about 300 12-inch singles and 300 45's a week, said younger sister Beverly Mizell.