First forgive me for getting in late and i may ask questions that are on this thread, didn't have time to look at all of them.
What kind of smoker and how big. Most guys using cook trailers are using insulated smokers, Stump's, Backwood Smokers, even Myron Mixon is selling a Stump's ripoff. These types have hardly any heat coming off them so they are mounted or secured inside and just dryer vents are hooked up for smoke ventilation. these are awesome because you aren't in the elements, (rain, cold, wind, nosy ass people).
I am gonna just assume you are using a round tank smoker, welded by a friend or bought that way. I say mount it on a trailer, which should allow for wood storage and maybe a storage box or two, depending on size of smoker. If this is your case, I say start with the camper you mentioned in the beginning. Modify it just enough to where you have ample Kitchen space and a fold up bed will come in handy at some point.
I will stay in touch now that the Football season has started and keep an eye on this thread for any more discussion, as I am sure there are more specifics to this