SOME “American Idol” veterans want to be rock stars, but Kimberley Locke aims to become a television mogul. The “Idol” second-season finalist, who finished third behind Clay Aiken and season winner Ruben Studdard, was spotted at Morton’s steakhouse in Midtown meeting with cable executives to pitch a new reality show on the search for the next plus-sized, all-girl music group. Locke performed her new dance single, “Strobe Light,” produced by “Idol” judge Randy Jackson, at Pacha last week.