There is no way to tell which would be the best buy. Things break and the older a vehicle, the more chance things may break. They may look great but depending on how they were maintained, they all may have a hidden, expensive, problem. Check all service records. Inspect the radiators for corrosion. Diesel engines last a long time but their expensive accessories do not. Do you want to sleep on and sit on 11 year old mattresses and furniture?
Check out everything or, if you are not qualified, bring in an expert.