2004 v6 mustang

I want to give my car that deep mustang sound. I have talked to a few people and they have told me to either get a new muffler or to replace the entire exhaust system. I'm not sure which is the right way to go with this. All opinions are appreciated.

2004 Ford Mustang 2dr Cpe Standard Gray Coupe. A Ford Mustang at Dave Syverson Auto Mall Albert Lea MN I'm not very car savvy, yet I've always been enticed by the Ford Mustang. So, I come to this community in search for guidance. The link I pasted above is a link directly to the dealer...