Exhaust 2006 Dyna Wide Glide

I am looking for a more audible exhaust for my Wide Glide. In checking with H-D local, they say the only way is to install a race tuner to be able to change from stock mufflers. Is this correct or are there some other mufflers available that give you more of a Harley sound than the stock mufflers. Also, is there any Race tuners that are good other than the H-D tuners? Do they negate the warranty on the bike?