Dual flowmasters are going to be your best bet. Nothing is going to give you that muscle
car sound except for a muscle car.
This is the best you're gonna get.
https://youtu.be/mSVH46L9Hag
Corsa Performance offers a cat-back, cross-pipe system for the V-6 Camaro that
offers improved performance, sound, and a reduction in weight over the factory
system.
The muffler is what shapes the sound. MRT 2.0 (9.5 lbs each):
The MRT ver2.0 is deep and loud and at wot it sounds like a Ferrari, so they say.
Long tube headers will also help shape your deeper sound.