Here is what we did. I was working for Dometic Service Dept., so I was familiar with their reefers, especially all the negatives. When we bought our GMC it had a Dometic RM 763 3 way. Before we started home with the GMC I disconnected the tag wire which was connected to the ignition switch, as I did not want it to operate on 12 VDC. A few years later we were on the way to Missouri and Emma said there was an odd smell in the refrigerator. I opened the door and smelled ammonia, so I knew it was dying. We made the rest of our trip with a cooler and lots of ice.
I decided we were done with absorption refrigerators, and I gave the Dometic to Leon Herschberger (National Refrigeration, Shipshewana IN). I installed a Frigidaire apartment size unit, which fit in the compartment with room to spare. It cost $267, which was much less than a replacement cooling unit for the Dometic. This runs on 120 VAC only, but we have a 2000 watt Trace Engineering inverter/charger which keeps it operating when we are traveling. The Trace inverter has a modified sine wave output, so I did a lot of testing, and found that the amp draw running on the inverter was twice what it was on shore power. I assume that this excess amperage was creating heat, since the compressor was doing the same work on either power source. It seemed to be working OK, so I didn't change anything. PS: I posted pictures of the installation on the GMC photo site:
http://www.gmcmhphotos.com/photos/showgallery.php?cat=5264.
That refrigerator lasted for 5 years before it died. I replaced it with another 120 VAC unit, which was still less cost than a cooling unit for an absorption unit, and a whole lot less than a new absorption refrigerator. However, this time I installed a separate true sine wave inverter which is for the refrigerator only, and the amp draws are same on either power source. That was in 2014, and it is still working OK. Our original battery was an 8D size AGM 250 AH unit, which did well for over 20 years. This spring I replaced this with a lithium/ion 100 AH battery, and will see how that works out.
This has worked out well for our use of the GMC. Your situation may not be the same. I have more details on the pros and cons of absorption vs. compressor models if you want that information.