Thanks All. Really appreciate your thoughts.
With a GM published tow capacity of 20,000 lbs, granted it's a lot of weight but GM would not publish that if the truck wasn't capable. I won't be close to pushing that. Also based on the trailers having good breaks. I understand from the Chevy dealer that the only difference between the 2500 & 3500 was an extra leaf spring. Same brakes and transmission. Since I knew that we'd be limited to <30' 5r there was no benefit to get the 1 ton.
I will be pushing 70' so I will be going to a large empty parking lot the first time out with both trailers to get the feel of it and the required spacing for 90 deg turns.
Looking forward to taking both to SD for fall walleyes in Lake Oahe in the AM and pheasants in the afternoon!