Welcome to the forum! We were in the same boat as you two: my wife wanted an enclosed shower and toilet...I wanted low-clearance capability. I asked a similar question a while back and Dave B from the forum posted pictures of this van that Sportsmobile West built for a customer in Saudi Arabia:
It has a Voyager top (fixed, fiberglass) and an internal shower/bath combo. Probably not much room to move around inside the bath "room" given the side walls on a Ford van are slanted toward the top.
Not 4x4, but Sprinter vans, with their nearly vertical side walls are better for RV-type builds:
Or this offering from Outside Van, a shower pan/drain with a shower curtain attached to the roof. You could also put a porta-potti inside the shower pan and use the curtain for privacy:
Good luck in your search!