Back in the day...
I towed a Jeep cj-5 (full size) with a little 22' winnebago LeSharo (4 cylinder turbo diesel) that looked just like this:
Google Image Result for http://worldcarslist.com/images/winnebago/winnebago-lesharo/winnebago-lesharo-01.jpg
and we didn't have no stinkin' auxillary brakes !
nor any special thing other than put the xfer case and tranny in neutral and go !
but understand if you want it...
My suggestion is to see how it does without it
and the braking system can always be added after the fact....