I use a simple unit, the Roadmaster, Brakemaster, it is a pneumatic cylinder the attaches to a bracket on the floor and the brake pedal. All you need to provide to it is an airline from the ouch brake system, it gives you true portional braking, an the cost is reasonable compared to many other units, also in and out in less than a minute.
Dennis & Debbie Z (Retired) F415847
Pipe Creek, TX
2008 HR Endeavor 40PDQ / 2014 Grand Cherokee Toad