5500-6000 pounds dry and 7000 gross for a max tongue weight of 900 lbs. replace the P rated tires with LT's, use a good hitch/anti sway system especially for the upper limits. I would suggest a tranny sensor as well as additional cooling if you are going to push it hard all day.
We tow our 25 ft ( not sure total length) 4200lb dry weight bunkhouse in the Rockies every trip which means a lot of steep climbs and descents. The 07 with it's better tranny is faster up the steepest stuff but on the open road both are so smooth that I tend to forget the trailer is back there and keep up with traffic. That is bad not just because of the trailer tires but also at those speeds, the MPG sucks.
We use a basic bar and chain WDH and a single friction sway bar. Early on I felt the smallest amount of sway when trucks passed us or we were hit by a gust of wind. Once I got it dialed in it it was solid no matter what passed us. We have had a blast of wind move the whole set up sideways but it didn't wiggle.
Our Expys have payloads of 1565 and 1745 lbs so we put the stuff in the trailer that can hold a additional 3000 lbs. No issues.
