Seriously now, if you don't have an answer for him, don't come in here trashing the thread. Didn't one of the mods make an anouncement about this recently?
Anyways, I'm sure if you search you will get better info that I can give you but a tuned pipe will help but only if you then properly tune your engine aftwerwards.
So, it is really about how happy you are with the speed of your truck from low to high end. If you have a nice tune on your engine right now and you don't want to mess with it, keep the same pipe