I would say a travel trailer (TT) would do you nicely. Most, even the smaller ones can be had with an in-coach bathroom that includes a shower. Of course, smaller the rig, smaller the space, including the bathroom.
Now, I am not a Ford guy, so I don't readily know the capabilities of your truck. However, maybe you do or if not, it is pretty easy to look them up on the web.
There is an absolute wealth of information available within the forums here and I'm pretty sure you can find a post detailing the same as you want to do.
Best of luck and welcome to the world of RV'ing.
Mark & Haydee (pronounced Heidi)
2010 Allegro 38QBA "Alle"
2008 HD Ultra Classic