Another thing to consider would be a Cold Air Intake. Lots out there at decent prices on eBay & they do add a decent throttle body (open carb) sound & help performance a bit too. Better would be getting one with a Heat Shield or making a heat shield yourself. Cold air is good!
I noticed a big difference with the sound after I put the cold air intake on.

 

I'd be interested in a vid of this. sounds about like what i want haha. Do you have cherrybomb mufflers too or what?

On another note, dual pipes out the side CAN be done on blazers.. http://www.youtube.com/watch?v=oKwra5iQ1sM

 

i can vouch for the dual exit exhaust on blazers, it just takes the shop a lil longer to bend the pipe and find room for everything to fit.

 

if you like a more raspy deep growl
the thrush welded double chamber and the duramax bullet will make it sound like a v8 until higher revs.
sorry bout the drunk guys lol
thrush
http://www.youtube.com/watch?v=h9VF_...e=channel_page
http://www.youtube.com/watch?v=sqp3wAcLMvU
duramax
http://www.youtube.com/watch?v=ieEffEMS9lI
glasspack (sucky sound imo)
http://www.youtube.com/watch?v=mZzk4...eature=related
flowmaster super 44 (purty good)
http://www.youtube.com/watch?v=vh25s...eature=related
straights with cat (little deeper then the thrush)
http://www.youtube.com/watch?v=8VilB8DsRoI

thats all i can think of right now.
im going with straights with cat or thrush or duramax with cat