This is a fun thread!
I really loved that little bus that I linked about a page back....
... I'm thinking my son needs a little project.
For a different business that I own, I drew out the plans for the interior of a 18'x8' cargo trailer and made it into a rolling store. Heat, A/C, solar panels, batteries, generator, sink, hot water, ice maker... it turned out pretty nice. It's tempting to gut that trailer and turn it into a sewing-mobile.
Then get a motorhome that is beefy enough to pull this trailer... lol... there's enough room in the trailer to put a Vespa or something to get around once parked.
I will say... the 5th wheel thing is nice.. you can drop the trailer and still have the truck to go fill up with more fabric and goodies.
That pink trailer I linked to is *awesome*... that would be a show stopper at campgrounds and at gas stations. It would be *really* fun to own.
About 10 years ago, I did have a 1969 vintage trailer - and I can't tell you how fun it was to own that. It got more attention than the million dollar motorhomes that would park next to me at places. Too fun.