Small water-heating wood stove

[Honus]

Is there such thing as a small water-heating wood stove? We are adding an apartment in our barn that will be heated with a hot water radiant floor. The same barn also goes through prodigious amounts of hot water in the wash stalls and other places. A wood stove would be nice for the apartment, primarily because wood stoves are just nice, but the apartment will be so small, I am concerned that a wood stove would put off too much heat to be of much use. If the stove had a heat exchanger, though, I'm thinking I could use it to heat water to be stored for use in heating the apartment and for use around the barn.

Does this plan make any sense at all? My gut feeling is that the savings on the gas bill will never pay off the expense of the system.