Jason,
The Webasto burner is still in production with very few changes from what it was in 1995. It is a very common heating system in over the road trucks and it is the heat source in the AquaHot unit, so finding a qualified tech should not be a problem, but parts are expensive. The Webasto burner is more efficient, much quieter, and it has a much higher BTU capacity than your propane heater.
I had a propane heating unit in my first Beaver, a 93 Patriot, and a diesel burner in my next 2 Beavers, a Hurricane in my 2000 Marquis and an AquaHot in the Solitaire. After having a diesel burner heating unit, there is no way that I would ever go back to a propane heater.
Gerald