Wow! It gets cold in Utah this time of year, doesn't it? Is coal to be your only source of heat, or do you have another system and don't dare run it because of the cost of fuel? With a house that big, unless each floor is a wide-open single room, you will need some way to distribute the heat -- it won't flow easily from room to room via doorways. Maybe a forced hot air system without the burner running, to suck air out of all the rooms, mix the cold with the hot from the stoves, and blow the uniform temp mixture back into the rooms? I don't know for a fact that that would work, but it seems reasonable.
As to where to get stoves, there must be other dealers? I would think you need a good analysis -- maybe hubby has already done it -- of how big the two units are to be, and what they should be designed to burn. I'm guessing something other than Pennsylvania anthracite is burned in Utah?