I have a 24 foot class C E-350 ford based motorhome. On good roads it rides great. Humps are handled with ease. However, pavement strips feel like 6 inch dropoffs. I just drove from south Florida ...
RV dealers don't generally work on power train and suspension, brakes, etc. You need to find a dealer who sells your brand of truck line and has facilities for RV work. For non-warranty work, a truck shop may be cheaper. Some work can be done without a lift by a qualified auto/truck mechanic.