Amanda Latona has a voice, but she needs a sound. It is January, and she is standing in a small, closetlike recording booth in Midtown Manhattan, where she is recording part of her first album for J Records. Her handlers are still trying to decide what kind of platinum-selling pop sensation she should be. Originally, the idea was that Latona, who is 23, should be Britney Spears. Latona admires Spears, and they almost performed together in Innosense, a girl group from the home of teen pop, Orlando, Fla. Innosense was designed to be an American version of the Spice Girls,...