Hi bob our trailer is 23 ft, the panels are approximately 26x48 x 4 panels, mounted flat. As for batteries I have six 305 AH AGMs, we went AGM as the batteries are mounted inside the trailer. The bank is slightly large for the array, but we have seen no issues the year the batteries have been installed.
My best advice is look at how off grid solar homes build systems and follow that route, they tend to be superior to RV targeted systems.
That is just my experience, I live off grid on solar, in a large home and just followed that type of plan for the trailer and it has worked well.