You have indoor storage, so maintaining the seals on a rubber roof will be minimal. Just avoiding UV exposure and the elements for six months of each calendar year makes a huge difference. Since moving to OH and purchasing the Minnie, we've had indoor storage and it has made a huge difference....roof has stayed cleaner and caulking has not started to crack.
You may want to do some research on TPO roof systems, which may be better than EDPM rubber roofs. Depending on what you decide about the two systems, it may determine what trailer you buy.
Just like most posters, I will tell you that I'm very happy with our current trailer, which is a Winnebago Minnie. There are several trailers in the Minnie line that meet your weight requirements. Because we do take longer trips, we chose the 2201DS due to the amount of storage space and the outdoor kitchen, which is something we really wanted. Overall quality of the Winnebago line of trailers is better than average. But, the seat cushions for the dinette had poor foam cushions for the main seating in the trailer. I had the foam replaced with higher quality foam more appropriate for seat cushions and it made a huge difference!
Other companies that I would consider would be Jayco/Starcraft (2 yr. warranties, look at upper level lines i.e. Jayco Eagle), Lance, Arctic Fox, Nash, and Outdoors MFG. But, take your time and look at a lot of different trailers and determine what will work for you.
