To really know what all the differences are, you should talk to a "very" knowledgeable sales person at a dealership that specializes in trucks sales for fleet and commercial. Some of these things change year to year and model to model.
Having said that, for instance on our '06 F350 diesel dually, getting the diesel in this model meant we got the stiffest springs in the front by default, due to weight of the engine. So camper pkg or not, it got the stiff springs. Being a dually meant it also got the sway bar in the back. In our case, the camper pkg actually gave us the camper certification, an extra overload leaf in the back, and if I remember correct the in bed 7 pin socket was part of it ( but I may be remembering that about the 7 pin socket wrong, as that may be part of the tow command pkg, or part of trailer tow pkg ).
As such, the option price for camper pkg was only $160 on this truck. So you can see that the pkg would likely be more on the trucks that do no already come with some of these heavier things.
As to the dual alternators, my opinion ( opinion only ) is that is more directed at trucks used more for commercial use ( ambulances, etc ) where they need a lot of alternator output at idle speed.
Not that it's relevant, but if you'd like I could post up a picture of the window sticker of this old '06.
EDIT: I have spray in bed liner in both trucks ( Ford and Nissan ) and I don't use a mat over them. Both have held up well from new, and I haul a lot of stuff in both.