Hi David & Jo,
I do not have any direct experience with propane fired cabin heaters, although we do have a propane hot water heater and love the on-demand convenience. What we presently have onboard for heat is an Espar D-4 Airtronic diesel heating system. We had the system upgraded from the Espar D-3L unit through Ocean Options over here in New England -
http://www.oceanoptions.com/espar_airtronicD2D4.html
The west coast rep for Espar is located in Seattle -
http://www.boatelectric.com/espar1.htm
Our system consists of the furnace unit with integrated electronics module, a bulkhead mounted thermostat and ductwork which delivers forced warm air to five registers located throughout the pilothouse, heads and cabins. This system heats up the spaces almost instantly and only draws 3 amps when away from shorepower.
Since all components are manufactureed and engineered in Germany, the system is expensive. However, I highly recommend it for dependable and efficient heat for any cold climate region. The Espar rep will determine the appropriate system to the size of your boat, but since your boat is similarly sized to mine, the D-4 should be well suited.