A lot of trailers today are aluminum framed so the only big structural things to worry about is the roof and the floor. RV's are not complicated to work on when needed. Find a floor plan you can live in and not be cramped up and uncomfortable.
Motorhomes will be more expensive to maintain in my opinion. I have a 37 foot Keystone Laredo travel trailer and we love the floor plan and the quality has been decent. I know you said in the 25 foot range but comfort comes with length. Look at shorter 5th wheels. A 30 ft. bumper pull is not that bad to pull and maneuver so don't just stick with the 25 ft. idea. Class C's with the super slide is another option for you to look at. Don't be in a rush to buy something and look at used ones.