I'd like to thank everyone who has chimed in and given opinions on my refrigeration decision. I still am up in the air on which direction I will go, but currently I am leaning towards a keel-cooled system over the powered cooler. I should note that I am really sold on the powered coolers, i.e. the Engel Fridge/Freezer units. The popular choice seems to be the Engel MT45F-U1 AC/DC Fridge Freezer which can be a fridge or a freezer, but I have my eye on the Engel MT60 Combo, which has individual freezer and fridge compartments.
However, the problem of where to put the thing on Windsong is perplexing me. After mulling it over, there are only a couple of options that would provide adequate airflow and decent accessibility from the galley. The first idea was to cut a big hole in the galley bulkhead and house the unit in the engine room as shown below:
The space on the engine room behind the wall would give it enough airflow to work. I could install some sort of door and be able to slide the unit out over the galley counter tops to be accessed. When done loading/unloading, you could just slide it back in there and hidden away. Of course, it would need to be solidly secured in place for sailing. Engel sells a Fridge Slide Tray for MT45F-U1, but not one for the 60. However, it wouldn't be too much of a problem make my own sliding tray for whatever model I would get.
Unfortunately, the simple issue of dimensions make this idea unfeasible. The MT60 happens to be shorter than the 45, but measures in at 31.1"L x 19.3"W x 17.4"H. The clearance of the bulkhead is right at 20", but tapers down to about 18" after the 19.3" width. Add in the need to clear the fiddles on the counter tops and the dimensions of the sliding tray underneath it, you are left with no space. Another hurtle would be the need for a platform/shelf in the engine room compartment for it to sit on. This space was used for the previous refrigeration components, and would probably be used for a new refrigerator compressor regardless. But the Engel unit would go further back and eat up the space where the starter battery sits, so I would have to find space for that elsewhere. Lastly, it would eliminate the already tough access to the storage compartment to port.
The second idea is to put it under the navigation table using a sliding tray to pull it out for access. This is the likely the best solution, but I would loose leg space and any hope of sitting at the navigation table. It might also require me to move the electrical panels from this area as they would be mostly inaccessible with the fridge in the way, in or slid out.
Sorry for the quality, this is the best one I can find without going back to get another one tonight:
The Engel's pro's are excellent efficiency in terms of power consumption, reliability, solid construction, can be run on 12v or 110v, and the advantage of being able to freeze or even have a dual-compartment unit with a freezer. The con's are: even if I get the biggest of these units, it will be only a fraction of the space of my existing icebox/refrigeration space. While I would gain the existing icebox space for storage, the placement of the thing is perplexing and I have not found a satisfying solution. On top of all of this I think I would want a bit more refrigeration space for living aboard here in the States, even if refrigeration space isn't as high of a priority while cruising. The existing icebox is only about 6-7 cubic feet as it is, and will probably shrink if I add insulation to it. The MT60 measures out to only 2.12 cubic feet. Since I will probably be living aboard for a while, I really have to take that into consideration.
I believe if I were to go with a keel cooled unit I would make improvements to the existing icebox in stages. First I would beef up the insulation to the lids as some Downeaster owners have done. I would also improve on the hinges and give the lids locking ability. The previous hardware would swing wide open in a roll-over. I would add some gasket/weather-proofing to the lids, something that should have always been there but wasn't. I will fill in the big hole/gap in the side that I showed in the previous post, as well as the large holes from the previous installation. Lastly, I will plug up the drain as it won't really be needed anymore. I won't make it a permanent plug in case I need to use it someday for whatever. The area below the fridge is inaccessible so improving the drain hose with insulation and a water trap is not possible.
With these improvements, I hope the efficiency of a keel-cooled refrigeration unit will be acceptable. If it isn't up to par, I will add insulation to the inside of the box until I am satisfied.
So while I have yet to make my decision on which direction to take, I am leaning heavily towards improving my existing icebox and installing a keel-cooled unit. I still am mulling over the Engel units and how to make one work, but I am not liking the "where to put the damn thing" options. Even if I were to get the keel-cooled unit, I would probably end up getting one of the much smaller Engel units to use as an efficient freezer.