I highly recommend hitting a cat scale. My rig is 38ft tip to tail and weighs 9100lbs. That is scaled weight. I have a dual cam and I have the 1200 lb bars. Mine has started to wander a bit because I need new ball joints in the front end but other than that the TT tows like a dream.
Not a 5er but our 38ft TT is 9100 loaded. That is scale checked. I bought a 06 Dodge Cummins. My choice was made by the following.
How much I was willing to spend. Then find all vehicles that fit in that category. Researched all the diesels and it seemed that the 06 Dodge had the fewest owner complaints for major issues from what I could find. It was also the better for mileage as it did not have the emissions stuff on it.
I get 20-25 on the highway, 16 in town, and 10-14 towing the TT. I never drive over 70 with it loaded or unloaded because mileage drops exponentially.