Greetings All,

I saw a Coleman heater at a sporting goods store.  Basically runs on propane
with tubes that are heated by flame and a blower to run the air through the
tubes.  It is sold as a tent heater.  You would put it outside the cab to
run and comes with flexible hose for the air supply.  I think you can recirc
air in the cabin.  Seems like an easy way to go, though there seems to be no
thermostat and you have to go outside to turn the flame off and on.

Rob G.