The closet your going to put it in would have been prewired and plumbed if the option was chosen by dealer or person that ordered the coach. My three Newmars all had the option.
Not sure about floor never installed one.
Some also will have a sticker on wall in compartment showing where to drill wall for vent location.
Washer dryers as seen in CW cat would work, I would get the vent one to keep moisture out of living quarters.
Your going to be a busy man with your projects.
When you want some KARMA let me know.