I have a rear radiator and I would not use that as my determining factor for choosing a coach. There is so much more to look at and worry about. I understand the issue with the rear radiator and not being able to easily access everything, but I have not had an issue and the people working on the coach have not had one either. I have a hatch in the bedroom closet that gives access to the air filter and the radiator and fan, and a large access hatch in the bedroom floor that opens up to the engine area.
I would first look at things like floor plan, manufacturer, age, care, records, and amenities.