Hey mate, I see you have been directed here via ozliberty by Shane.
Although I can't tell you what exhausts will be quiet without drone (except K2 gear which is insanely expensive and I'm guessing you aren't looking to drop $1000 just for a centre pipe)
I can however point you to this thread, and you will at least be able to have a look at what some people have put on their cars and how it sounds.
viewtopic.php?f=55&t=2382&start=0Keep us updated on what you choose.