Im in the same boat here. I have found the following at home depot that im looking seriously at. The first is 4 cubic ft and is approx 22 1/2" deep, 20 1/2" wide, and 45" tall has a stainless steel finish to it, the fridge is seperate from the freezer and uses .95 amps, cost $199. The second by the same company same width and depth but stands 58" tall is 8 cubic ft again seperate fridge and freezer, uses 1.4 amps.
Well, 1.4 amps at 120 volts is gonna be more than 14 amps at 12 volts, due to the inverter inefficiencies. I guess you could do it, but that's a pretty heavy load to run thru the wire from the alternator, thru the connectors, all the way thru the fuse block and back to the fridge.
If you decide to go that way, you might wanna check all the connections, at least, if not upgrade some wire sizes... I'd sure try it in the driveway for a few hours to make sure none of the smoke gets out of the wires...