The ones that have legitimate shots blowing up that are new to the country are Clyde Carson, J. Valentine, Mistah F.A.B., and The A'z mainly because theyre all on majors. 40 and Short are both big on a national level and current, especially 40. If Yuk (or RAL) decide to drop MDMP before the world ends I think he has a shot of getting national attention, and the same goes for Ya Boy.
Personally I would want to see Mess, Clyde, and J. Valentine all blow in cuz IMO they're all talented artist that have the national appeal.