newbie need help in setting up the right things for the camper

i just bought an used cab over camper, and i will need a small refrigerator and a outside shower.  these cab over will only be used for 6 months in a year and may be for a period of 2 years total until my special project are finished. then i am going to sell the truck and camper all together and get something else which i do not have a solid plan yet.

now, my camper has a storage cooler box which is not electric cooled and a propane stove, oven, heater, and it is all 12V system, and there is no 110V and i have 3 choice:

i can buy some solar panel, inverter and charger and plan use up batteries and i have a lot of 12V batteries 24AH which i can use as i have at least 12pcs in stock sitting in my garage and buy a regular 120V refrigerator which is a lot cheaper than a 12V refrigerator or propane/110V refrigerator. 

i can buy a 110V/ propane operated refrigerator and take off the cooler box which is next the oven and put in the same space where the cooler box is. but my exisiting cooler box is about 1.7 litre which is the smallest size cooler in the market instead .

i can buy a 12V electric cooler which i do not know if it work to cool the meat for a few days under yuma arizona day time as they say it is 40 degree less than the enviroment temperatuire which may be 100 ~ 110 degree in yuma in the day time during the months of nov to apr.

what i need is only a 1.7 litre in size refrigerator or electric cooler not really a big one.

i do not want to keep the budget low and be able to maintain a self sufficient camper during these period of time.

do anyone has done this kind of upgrade on their camper before? any suggestion are welcome.

Where are you located? 

What kind of camper did you buy?  Brand, model, size etc.  Solar would be expensive, enough to do what you want woud likely cost as much as a fridge.  Will the project have 110v available?  If so, easiest way would be to get something like a dorm fridge.