I installed a "digital" t-stat in my Coleman with the propane furnace.  The
stock stat mounts next to the floor and did little in the way of maintaining
a constant temperature.   Don't recall the model, etc. but it was the
cheapest I could find at Home Depot.  In order to get one with an OFF-ON
switch I had to buy a unit used for both heating and cooling.  It's hooked
up parallel to the stock OE unit.  I mounted it as high as possible.  I keep
the original stat in the OFF position.  If the digital one fails, I can
still use the stock unit.  Other than replacing the batteries yearly, it has
worked fine.

I was going to replace the thermostat in my PU because I thought it was
junk.  But I realized that they come preset from the factory with the
anticipator set to the max.  I adjusted the anticipator to the correct
line voltage setting and my PU is a comfortable as home.

Going with a digital unit would be nice but a little overkill, a
conventional thermostat works just fine.  Plus, one less battery to
have to deal with.

Dave