Thanks for all the input. I am looking into a Corsa cat back system. They say there is ni resonance in the cabin at speed and they come in both a sport and touring (quieter) muffler. Cost runs about $700.00 for system but my Dodge dealer says they use it and have had good results. Corsa has sound bites on their website so you can theoretically hear what your engine will sound like under a number of different conditions.

 

Gibson dual extreme is great, got mine (power wagon specific) in all stainless through Summit Racing for $512.