Looks like these other guys have touched on some of the other questions I was gonna ask next. One more thing I would consider is whether or not certifications would be required / attainable for the various systems that would be installed.
I AM hoping you can make it work! I DO think you could find a niche, as there is obviously a demand for skoolies based on the number bought and sold annually. IMO, & based on what I've seen for sale, most (but not all) converted skoolie sellers do not get out of it what they put into it. Of course, those don't quite fit your pattern as they are more "labors of love" than trying to target / create a market.
As long as you've got yer I's dotted & T's crossed, you should be able to do it!
~(G)Q Arduously Avoiding Assimilation