I have a JKU 2015. Not sure the amount of space you are planning to set aside for the refrigerator. I purchased a SnoMaster 56L Refrig/Freezer, usually just use it as a refrig. I mounted it on plywood, used a 26" full extension drawer slide, which fits nicely in the JKU, the extension really allows great accessibility. I'm usually gone for 4-6 days at a time camping/fishing on the beach.
Think ahead before committing to the overall purchases-just saying. Refrig and supporting items can take up a lot of space and tie up a lot of dollars.
When your out 3-6 days (or more), ice is not an option for me-no place to purchase ice. How are you going to power the refrig?
My set up is follows:
Snomaster 56L classic refrig/Freezer---excellent unit-love it-would purchase again
Slide shelf-drawer slides---a must, refrig weights 56#, but when loaded down it's hard to slide forward enough to get access to the rear compartment .
Renogy 20 amp Rover charge controller
Renogy 20 amp DCDC charger---a must see below***
100 watt Mono crystalline folding solar panel---would possibly consider a roll-able flat type panel-(less weight/bulk)
Renogy 700 watt inverter-can't do much with 700 watt-will more likely replace with a 1500 watt at some point.
Renogy 100 AH LiFe battery, mounted in an Atwood battery box with a 100 amp and 30 amp circuit breaker mounted to an angle piece of plywood in the front---the LiFe battery is great because you run the charge down to a minimal amount. I have the refrig/freezer set to cut off automatically at 10.6 volts.
ALL components are installed using Anderson Plugs so the components can be removed/replaced as needed. I installed a separate chassis ground to the rear seat mounting leg-again with an Anderson plug.
***I just recently added the DCDC charger to the rack (system). I found many times when I left early in the morning, by the time I got to where I was going there was little or no sunlight left. I couldn't set up the solar panel. Usually by mid morning the next morning the refrig/freezer would stop. Keep in mind most of the time the unit is pulling 0.06 amps (not much). By adding the DCDC charger-now when I arrive the battery is still fully charged.
If you need more help I can send more pictures and details -just let me know.