With regards to width,
I say go as narrow as possible as it provides huge benefits.
The only negative? It detracts from usable interior space.
For us though, our (narrow) camper is a game-changer. Ours is 82" wide as I recall with a 78" interior width.
Overall height is 10'4" We scrape under trees often, and trim as needed. But if it fits, it ships
We just finished a trip that involved 70+ miles off the pavement on little more than single track Jeep trails with nasty drop-offs, and any wider would have been a serious problem.
We came head-to-head with 2 vehicles on the trip, and each required one of us to reverse more than a 1/4 mile to find a pull-out large enough to pass....
Height will always be a concern for a hard side slide-in, but when the width is similar the width of the vehicle, is is considerably easier to manage.
And more power to ya if you can get this segment rolling.
![Thumbs up (y) (y)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
There are loads of reasons why we decided upon a custom flatbed camper for our needs.
I hope more and more people realize the huge benefits of a flatbed camper on a sturdy, comfy full-size pickup.