Oh, the Jack... A loaded Class C weighs 7 tons or less. About 4.5 on the rear, 2.5 on the front. So in theory a Four-Ton Bottle Jack would handle it, since we only lift one "corner" at a time. Problem is, we don't get to lift just a corner, since the jack ends up toward the center of the rear axle. And, we get a very poor angle at the jack under there. A Ten-Ton isn't all that common, but I happen to have one and it works pretty well. I bought it because I thought my Twelve-Ton had died. Since then I've used the Twelve on most of my work and I like it. With so much extra capacity, it lets me pump it at odd angles with a shorter handle.
This is a Twelve-Ton Low Profile Jack.
Twenty-Ton would be still easier, but remember the jack has to fit under the axle with a FLAT tire, and Twenties are pretty tall. Also pretty heavy to position under the coach.
In addition to the jack, we carry a "four-way" wrench for truck wheels, a jack stand, and a thick plywood square to support jack and stand on soft ground.
You may not want to actually change a flat, but for many of us it makes sense to be equipped to be able to do it.