Don't know of a 12/24 Volt model. In the US, the predominant models are the Raritan and Uline. I have a Uline and no complaints. Had to replace the ice maker unit on mine, at least 10 years old, perhaps more, but I think it may be the same component installed on the Raritan. If I were to replace the whole unit, I'd probably pick the lowest cost of the two.
The counter top ice makers are much less expensive, and if they meet your needs will get the job done. Heard good things from cruisers who have them in the Caribbean. But, I like the ease of just reaching in and grabbing the cubes. We have found when energy challenged we can make a weeks worth in a day and store in the freezer.
I will second the suggestion for outside, versus inside due to heat. Especially if it's easy and protected from the rain. I'm not sure it pays to build a new outside wet bar for one though,
Good luck! Bob