The pic I posted earlier had a 1000gal on the right, 2-fryers, 48" range, 24" griddle, and 2 star burners on the other side.
I did mention putting 2 back there, rearranging the needed pieces from the other side to another spot in the trailer, or using 2 of the rotisserie style pits from the hawaiian rig Imma linked.
Although, now that I think about it, would the pits need to be enclosed like that setup? Throw 2 pits side by side at the back, similar to that pic. Let the roof cover the pits, but don't enclose the sides. Might be better to do a reverse flow in that setup though. Get the stacks to the back of the rig and away from the enclosed part. Move the fryer/range/griddle/stars to the inside portion, and layout from there. Keeping the aisle between the pits, so you can more easily get things in and out between the pits and the "kitchen" area.
That might help with the heat a little more, as opposed to being in a pony wall/screened setup like the pic.