I have also been looking at that model, but need a new TV to do it. We were looking at upgrading to a 3/4 ton anyway, but with the weights on that Jayco, a 1 ton will probably be in the cards. 18% of GVWR is 2565lbs, so I would agree that your 2500 will probably be over the payload.
That being said, you probably know how these types of conversations go on the forums so I won't get into that part. I did receive one pointer in another thread that I took to heart:
- if you have a 3/4 ton, you'll be over weight but it'll haul it - how you react to that info is up to you.
- if you're looking for a new TV, don't even consider the 3/4 tons.
Given that you have a 3/4 ton already, and depending on how far/much you'll be towing, perhaps some airbags, keep things as light as possible, and get working on getting the 1 ton