Thunder Mountain either system should work to power the BB2, and keep it from draining your battery. The plus to the Cooltech might be if it's all using the same umbilical cord vs having a separate line to deal with.
Now whether you need it or not, only way to know is to give it a test run and find out. Just make sure you have a way to charge the Jeep in case. I just can't imaging the system drawing that much power to totally drain a newer Jeep battery, sure maybe an old one that's already near end of life.
In all my reading about the various BrakeBuddy systems (select/classic/stealth) I never found one with a built in battery, they come with the charge cable and the remote sensor in the motorhome has a battery but that's all. There are none listed on the accessory page either.
