um just a diff back will give you the rumble you want thats all i have and it sounds nice. pitstop, any muffler place can weld you one up. size asny where from 2.5" up realy. brands dont realy mater to much. um any where from $100 up realy. if its to loud the police might not like you and vtnz probly wont pass you as your ment to have a cert for an exhaust these days. no realy gain from putting 1 on apart from the nice sound.