Hope IM not out of turn here, I can respond
to part of the question. Chris has 22/5s. The hitch height at the top of a Holland hitch is generally about 46" high. I don't think Chris installed an air ride hitch, but IM not sure.
Most of these tractors have air slide hitches. The kingpin on your trailer fits the Holland like a glove.
The chassis suspension on air ride tractors is self adjusting. They adjust to the amount of weight placed on the hitch. The owner can lower the height about 1/2" without a problem.
Doing this tends to soften the ride even further.
I should have a 99 Volvo with autoshift identical to the one on the site below ready to go in about 4 weeks if you have any interest.