Very nice GMC has a pipe ready to go and muffler if you were interested becuase there isn't many others I think there is a Jemco pe400 pipe if you can find one I put Geoff's pipe on and noticed a power difference and not to mention it looks a heap better than stock.
I also got some works performance shocks made up to suit my weight but at stock length they work great.
Here is the GMC pipe it was patterned from my pe400x and installed on my pe400t fits both and the muffler is so much better than stock not to mention repackable I am not a sales rep for GMC though but higly recommend him