Another option you might consider is CNG (compressed natural gas).
Unlike propane, NG rises, and that opens up a whole bunch of storage
opportunities. Once thought of as the best solution for boats, CNG
has fallen out of favor, as it's expensive or impossible to refill in
some places. In my way of thinking, that means you might find someone
getting rid of a perfectly serviceable CNG rig for next to nothing.
If you'll be cruising in areas where CNG is available, you might be
able to set yourself up nicely without much of the PIA you describe.