Very cool build, gives me lots of ideas.
Also on your heater what brand is it? If its an Esbar and you run into any problems hit me up. The trucking fleet I used to work for ran them, so I have a fair bit of experience with them.
Tons of people have asked. So here it is. I itemized the cost of all the materials. It turns out that I spent around $5k including everything. I fabricated everything instead of building premade. I even did the 4 trailer jacks.
I never get tired of looking back on your builds. Knowing how much trouble you had with your knees over the years makes what you have done even greater.
I hope your most recent surgery has helped you deal with it.