If you do not have one now then I would recommend a TruckFridge.
Ours, TF45 12 volt,has been great. They come in different sizes so you should be able to find one to fit your needs.
It is a fairly easy install. They need a space to slide into and a 12 volt power line with a fuse. This is my install, http://www.sportsmobileforum.com/for...fan-10171.html
Read detailed trip reports, see photos and videos on my travel blog, luinil.com.
Current van: 2002 Ford E350 extended body camper with Colorado Camper Van pop top and Agile Offroad 4WD conversion.