Its all about acoustic tuning and while I think its possible and Ive seen examples of it, I dont know what all is needed. I have also seen my fair share of examples of GP's that sound friggin' SWEET at idle but get them up around 2000 rpm where you do most of your highway type driving at, and it gets raspy and has a drone to it.
So to ultimately answer your question you may have to wait for input from others. I know there are some combinations out there that work well. Heck, using stainless steel over aluminized type pipes will give you drastically different sounds.
