Guys sometimes you may be better off just going with a custom exhaust. you can get exactly what you want, and can be cheaper most of the time. for the sake of maintaining warranty's I would suggest not going with fully welded systems. try to retain the factory band clamp locations. my dealer stressed that to me, and dont mess with the cats.
Donelam304, 300$ for a new muffler + new routed piping isnt a terrible price, but probably not the lowest possible. think about any name brand kit that gets released right now. they are gonna be over priced because of the immediate demand.
also I believe I read that the 6.4L exhaust is factory 3.5'' correct ? does anyone plan on going to a 4'' tail pipe ? or would the loss in back pressure to be much to start losing low end ?