Fridge

depends if you want to conserve space and only keep bare essentials or get the largest you can afford (space and size is not a factor). I personally can get away with a very small unit that can set next to the passenger seat (accessible while driving) and it's a black & decker bought several years ago at Walmart.

 

In the smaller/economical lines, they are all pretty much as good as another. So long as you bring them home every 6 months or so, open them up and clean out the fan and intake area of dust/dirt, they'll typically not give you any trouble. I've found the "more expensive" units don't generally outlast the less expensive ones. Whatever is available and seems appropriate. The bigger ones will have to be situated in the sleeper area. Keep them stocked well but not "packed tight" and they hold cooling fairly well. Try not to add "hot" water/beverages as these will warm up the unit for 3-5 hours until it can re-compensate back to it's normal cooling.

Try and replace the cold stock consumed daily, every night just prior to retiring, for the next day.

 

ENGEL is the way to go but they are expensive. I have two, one that can heat or freeze, medical grade, that has a digital set temp. The other is a fridge/deep freeze that I can keep frozen tv dinners, popsicles etc and holds at -15f. They are both 12v and just plug into the cigarette lighter. The compressor only has one moving part and they are designed to withstand tilting and vibration. They are both very low draw and I've run them for two days without the truck running and had no problems. I use the freezer to freeze and refreeze polar ice bags that I then can rotate into any cooler. Because these are not thermo electric they do not rely on ambient temp. I've heard of people that have had these in service for 10-20 years without a problem.