Just as another possibility, I think I'm going to install the Vitrifrigo 130. Reasons I like it over the Isotherm:
1) I prefer the freezer arrangement/size.
2) I like a full sized (depth) bottom shelf. My SMB (smaller Norcold) unit had this style and I liked being able to just sling milk and heavy items onto the bottom shelf (vs. fiddling with a little plastic half depth crisper or something).
3) They make it either with a typical, built-in compressor, or with a separate compressor. I like a separate compressor for a few reasons. One is that you can insulate the heck out of the box (since it doesn't have to vent the compressor), and two is that there is no "notch" taken out of the space (so it is slightly larger). Three is that I can sound insulate the compressor more easily (Isotherm may offer this style as well, not sure.)
Both Isotherm and Vitrifrigo are well thought of in the boating community, so as brands I like them both; hence my preferences are about the form factor and I don't think you could go wrong with either. I have also heard good things about Nova Kool but have not been involved with one.
The one I'm going for is Vitrifrigo C130RBD4-F. This is "regular" or it comes in "steel." (There isn't anything really different, but just stainless steel trim on the latter. I prefer the regular -- you can still change the door panel to whatever you want). Vitrifrigo doesn't have "ASU" like Isotherm does, so that may be a factor. I like the form factor on the Vitrifrigo so will likely use the "keep a blue ice block in there" method of holding cool at night.
Vitrifrigo available at Sure Marine amongst other places (Defender, etc.). I'll link to it on Sure's site since I like the way they show them, and they also carry Nova Kool in case you want to look for comparison. The C130BD4-F is shown at minimum advertised $996 but their actual price is less. They estimated around $100 or so in shipping to AZ. They are a great, "real" shop in Seattle with not only refrigerators, stoves, etc. but all the parts and pieces (and expertise) a real person walking in in the middle of a project would need. I like that.
http://www.suremarineservice.com/C130RBD4-F.aspx
Defender might be better for you in a more easterly location and they are good too (but not as much of a dedicated refrigeration/heating type place as Sure) (not that that should matter in this case).
http://www.suremarineservice.com/refrigeration.aspx
In case others start to think about refrigerators while reading, Vitrifrigo (and I believe Isotherm) also make some really nice drawer refrigerators. They could be nice in a location where the refrigerator is really close to the floor (vs. bending over to get in the door).
Lastly, there is a company that makes super-insulated, custom sized refrigerators for boats (or vans
). I'm sure they are not cheap, but the people I've spoken with who have them, love them.
http://www.seafrost.com/
Lastly, please decide, order, and install before I do mine so I can try to copy all your cool ideas