I would suggest a unit that has a door between the bedroom and living area. You gotta have that privacy sometimes. I would also think a larger bathroom would be beneficial to full time living.
Having no idea what kind of tow vehicle you have nor your expectations, I will say look at the Grand Design Imagine line to get some ideas. They offer the features that would be important to me long term.
Study up on preventive maintenance too. Almost no matter what you choose, you will need to climb on the roof for inspection and waterproofing, among many other things.
