I also looked hard at doing this in a 16' Side Dinette and the real problem was getting the floor pan to create the shower.
Scamp will not ship an item this big and fragile and so I looked to alternatives of my own.
I fashioned a laundry room sink into a suitable pan and was in the process of getting it installed when I found a Casita
and bought it and I sold
the Scamp as it was.
Good Luck if you try it but it will be much easier if you need one to buy it that way.