Behind a motor home you wouldn't need auxiliary brakes. If you wanted them, almost any trailer shop can install brake hubs to the axle and install a brake controller.
A 6x12 should have a brake axle already. 7 pin plug? Battery mounted on tongue? Wire going to hub from trailer frame? If so, electric brake axle. If not, like I said, local trailer shop can install.
Bob and sometimes - Nina - a Staffordshire Terrier/a SPOILED pit and her kitty Spaz
2006 Dodge SLT 2500 4x4 Cummins Quad Cab w/AT and 3.73
2007 Salem Sport LE 26FBSRV (TH) w/ my Victory Motorcycle in it or a EZ GO Shuttle cart.