Just kidding! I’d probably shove the tank as far forward as possible and run your plumbing along one wall to free up floor space. With enclosed trailers you can really get creative. I saw one guy on here that mounted his surface cleaner on the ceiling. Put hooks on the doors and hang stuff from there as well.
I wouldn’t mount the reel on the ceiling but that’s just me. It would be a pain in the neck to reel up 200’ of hose full of water at that height. Do this: Trace all of your equipment’s footprints onto cardboard and then play around with the cardboard set up in different areas to see what works best
Pretty sure that was @Clean_Blue - Can’t find the pic, but he made a ceiling mounted front end cubby for the head of the surface cleaner with the arms secured up top as well. Not sure how else to describe it, but it’s pretty sweet. Lol
Those two pictures should give you a lot of ideas. Notice how he has his plumbing run across the ceiling go keep it from cluttering the floor. Also keeps you from tripping over it and knocking your teeth out on the handle of your machine.