We've had two Class C's with HWH Kickdown Levelers. Both manual control. I don't know who installed the first set, the current ones were installed by CW.
I like the idea of Levelers, but Kickdown has been a PITA on both coaches. They extend before kicking down. They fold part way up but the rams don't retract. I also think they wobble when deployed.
So, if I was to install them again, I'd want direct acting or probably would not bother with jacks. I'd suspect that availability of direct acting jacks for Class C depends on Chassis Manufacturer, Location of Obstructions on the RV body, and Design of the Jacks and Brackets.
EDIT: First coach was 24-ft, Second is 31-ft. The longer the coach, and ideally the wider you can set the jacks crosswise, the better they'll work for you. On the 24-ft, we'd often lift a front wheel off the ground before the coach reached level.
