Want to install an Atwood heater in Jayco Pop Up

Hello, 
We just bought a 95' Jayco J-series pop up.  It does not have a heater installed and we really want to have heating capabilities.  I have found an 18,000 btu Atwood Heater.  My question is: where do I mount the heater?  Is the vent already in the camper or will I have to install a vent?  Will I need a thermostat?  Is 18,000 btu big enough?

Or...
Thought about buying a Mr. Heater Big Buddy and hooking it up to the LP in the camper.....Has anyone ever used this kind of heater, and does it work very well? 

Also...
Thought about getting an electric heater for when we have electricity hook up.  Any suggestions?

Any suggestions or guidance is greatly appreciated.

An rv furnace such as the Atwood or Suburban, is mounted with the combustion chamber, burner, etc. accessible from the outside. so you would need some kind of storage bay to put it in. Your rig may already have one designated for it, and may also have the necessary propane plumbing and hot air vents already installed. If not, you can do it yourself but it won't be easy. In addition to the above, you'll need to install a thermostat, and run some 12volt wiring to it. Check with Jayco about your specific rig; you may get lucky.

For electric heating, many of us carry those small 'cube' or 'milkhouse' heaters, and use them when necessary, and store them when they're not. One or two might take the chill off, but they're not a substitute for a good furnace in 20-30 degree weather.

The Mr. Heater Big Buddy would not be my choice for a portable heater for a couple reasons. First, the literature say nothing about it having a fan or other means of circulating the heat. Other Mr. Heater units do. Secondly, it says it has settings for 4,000 or 18,000 btu's; 4,000 being barely adequate (A cube heater puts out around 5,000 btu's), and the 18,000 setting is way too high for most purposes. There is no thermostat from what I can tell, so you would manually have to turn it on and off to maintain your comfort level. There are other catalytic units out there that are more suitable for mounting permanently on a wall or setting on the floor, but these too have no automatic thermostat. They do, however, have a control to set the heat level anywhere from the lowest safe setting to the highest, and anywhere in between. Whichever model you get, get one that is capable of hooking up to a 20lb propane cylinder that you can set outside. A one or two pound cylinder won't last long at all.