F. Gary Gray is in talks to direct Straight Outta Compton, the N.W.A biopic set up at New Line. Gray beat out contenders John Singleton, George Tillman and Elgin James for the gig.
When I think about rap groups of that era, N.W.A. with the break-ups and the feuding, and actual violence (Above The Law vs. The Lench Mob) is probably the best choice for film. Death Row Records would be another good one.