An electronic two speed switch would work great.
One came on my US Gear OD and then with my brake a friend attached a braket to the OD braket and installed a $10 Pull-Push switch from Car quest. CAUTION Some switches Rattle w/ truck vibs My OD one doesn't the car quest one does. I believe I read some gys got something from BD too.
Locally an Truck Air brake supply place I saw some. Or contact US gear maybe they'll ship you a shifter switch amd braket.
Works great 2speed at 9 o'clock on stick Large red knob. Small yellow slightly lower the 2 speed and at 6 o'clock. Love it.
james