I have towed my Jeep many miles and never use a supplemental brake unit. I don't believe that most states require these as many of the manufacturers state.
NRS is Nevada Revised Statutes
NRS 484D.255 Requirements for performance.
1. Every motor vehicle and combination of vehicles, at all times and under all conditions of loading, upon application of the service brake, shall be capable of:
(a) Developing a braking force that is not less than the percentage of its gross weight tabulated in subsection 2 for its classification;
(b) Decelerating to a stop from not more than 20 miles per hour at not less than the feet per second per second tabulated in subsection 2 for its classification; and
(c) Stopping from a speed of 20 miles per hour, in not more than the distance tabulated in subsection 2 for its classification, such distance to be measured from the point at which movement of the service brake pedal or control begins.
2. The required braking forces, decelerations and braking distances are tabulated as follows:
Brake system
application
Braking and braking
force as a distance
percentage in feet
of gross from an
vehicle or Deceleration initial
Classification combination in feet per speed of
of Vehicles weight second 20 m.p.h.
Passenger vehicles with a seating capacity of 10 people or less including driver, not having manufacturer’s gross vehicle weight rating....... 52.8% 17 25
All motorcycles and mopeds............................ 43.5% 14 30
Single-unit vehicles with manufacturer’s gross vehicle weight rating of 10,000 pounds or less 43.5% 14 30
Single-unit vehicles with manufacturer’s gross weight rating of more than 10,000 pounds 43.5% 14 40
Combination of a two-axle towing vehicle and trailer with a gross trailer weight of 3,000 pounds or less 43.5% 14 40
Buses, regardless of the number of axles, not having a manufacturer’s gross weight rating 43.5% 14 40
All combinations of vehicles in driveaway-towaway operations 43.5% 14 40
All other vehicles and combinations of vehicles 43.5% 14 50
Under 40 above is the combination you are looking at. If you can stop as provided you are ok. If you think about it how could a tow truck ever legally tow a car if a brake unit was required in the towed car. Check your State's laws.
Adjustable tow bars are easier to hitch up because their sliding arms can be aligned to the ball without the Jeep being in exactly the right spot. As you pull forward they extend and lock in towing position. My bumper has the ability to attach a tow bar to it so I just use a Reese A-frame style bar. Just make sure that the bar is level when towing. You didn't say what year your Jeep is but my 2006 was easy to wire for running and brake lights.