Unfortunately, they don't grow on trees and they don't advertise themselves as such. I suggest you find yourself a really good inspection check list. Then start calling RV repair businesses and asking questions. Depending on a technician's travel time and the depth of the inspection, you may pay up to $500.00, with no guarantees on the inspector's part. These are all things you can negotiate with the shop or technician you engage.
You might try looking at www.rvservicereview.com
for a start.