Why don't you use one of these Espars.
EsparIt seems to me to be a bit of a safety hazard in a TC because of space and clearances reqired for the flame burner box type...in a MH it could be nice and comfortaing to have a flame going. Particality for heating, I wonder!
Also when at the Espar site look at all the heaters for semi-trucks, neat stuff. I had also thought if the OEM propane blower heater ever died, I be installing an Espar...and using the same ducts I have now. Deisel truck deisel heat, no brainer!
Good luck and make sure you post install pics and explanation. This should be fun.