OK, let's start at the beginning:
Mount new tires on the coach.
CHECK RUN-OUT. Balancing an egg-shaped tire will NOT give you the ride you want. If over .035" run-out, rotate tire on wheel, etc. Basically get it fixed. If nothing else works, have it trued. Almost a lost art, but there ARE people who still do it.
THEN, and only then, best answer is to balance the tires ON THE RIG. Balancing the tire/wheel to within 1/2 ounce is great, but your brake drum/disk likely weighs close to a hundred pounds. Easy to be a couple of ounces out of balance.
Another option is something like CENTRAMATICS, that automatically balance "all rotating masses".