If I'm not too late...
I've got the Invisibrake in our 97 Jeep Wrangler and LOVE it! It is one of the easiest supplemental brakes to hook up AFTER initial install. After install, there is nothing to do except hook up the tow bar, safety chains, and electric connection to the towing vehicle. You still have to make sure the steering lock is released if applicable, as well as having the transmission/transfer case in proper towing configuration.
For a do-it-yourselfer, this is a PIA project in my opinion. It took me a couple days (I'm slow I admit), and I left some blood along the way. Once completed, I think it was worth the pain and effort.