You will want a controller with full proportional braking, these will have an internal sensor for rate of deceleration, and do not depend on a brake light feed to activate.
Your coach may be wired from the dash to the trailer plug, that will shorten the install time . Phoning the chassis manufacturer should provide this info.
You should also check out you coach, to see if the brake light come on with the engine/exhaust brake. The installer will need to know.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.