1972 El Camino- exhaust?

ok i have a 1972 el camino, 350 v8, edelbrock performer intake, edelbrock 600cfm carb, have stock heads. now i need to get rid of this old exhaust thats on there, came stock with glass packs from the factory, i cut the pipes (had dual exhaust of course) about 4 inches from the rear end with about 18 in of coming from the glasspacks. its already loud but the exhaust that has been on there is worn out etc, and has some back pressure issues because of it being old and glasspacks. now i was thinking new 3in pipe or maybe a little smaller coming from the exhaust manifold and going straight down into either any type of cherrybomb muffler or magna flow and then going straight from them to the rear end (still 3in pipes out or a little smaller). i want this baby to roar cause i plan on doing a lot to it, im about to paint it soon as well. what do you all think i should get?