That Eshland 260 is good for an honest 260K and I have a couple along with a dozen AA's. I did have an early Eshland 130K that had an auger, twisted belt AND a separate gear reduction motor to do the ashing. They will do the job, however the hopper arrangement kind of makes one want a feed auger. Is the one you are looking at an indirect drive model for the blower? The heat from the swirl chamber will telegraph back through the motor shaft on direct drive models, consequently, I prefer the indirect. Also, no vibration with the indirect. Direct drive uses a Jacuzzi pool motor and they are 3/4 hp as I recall. vs 1/3 hp on the indirect blower drive configuration. No hot air models, only Yellow Flame, if you can find one, or Keystoker for a well made current BIG unit.
Leisure Line has two kick ass models at 110K and 220K and just for kicks, as you mention power outages, I think a auto start gen-set might be on the wish list. Many used ones available that are affordable and make excellent back-ups, or prime power. I know of a 50K Generac that is brand new but never used..... all wired up........in a heated mechanical room that could be for sale. It is 3 phase, but a nice unit. If you wanted to use a coalgun, you could use modine style heaters very effectively and stay with hydronics..
If you are looking to heat the plant and need to replace a great deal of the piping, perhaps a retro to warm air is the best solution. I never can say I built for the 'weakest link', but lately I am thinking the 'Gene Pool ' is without water judging from the topics that pop up here. Old timers have seen many very bad situations, and are merely trying to save another generation from the same fate. I respect them. too bad more didn't.