Thinking about fabricating one out of an old cooler- cutting in a view window. I have both aquarium heaters and an old electric hot water heater thermostat. I may just roll with the aquarium heater/water in bottom way. Easier. And you have the moisture aspect covered, as to where the light bulb/thermostat type of heating you have to try to add moisture with wet towels and such. Seems an 1/12" or so is plenty of water, and just shield the heater from the cooler with a tile or shroud it somehow. Then just build a rack above- I am thinking wood slats. Should make the turning process a bit more orderly with slats to hold them. I read about this a couple years ago- I recall people were saying 3/4 is about the most you want between slats. And- In theory you can make a few coins selling eggs. We just give the excess away when we are swimming in eggs. No shortage of friends who want them. I also give some to the trash guy now and then, that sort of thing.