I've been looking too, mainly at the Ram because some 2019's are still available and the prices are 40 or less on the tradesmen 2500's. The 8 speed seems to be an improvement and the folks on here with them dont seem to be having too many issues.
The new Ford would be my preference, but a new Engine AND a new tranny all in one year worries me.
As to your towing , maybe take a look at the TFL Truck guys videos, they have recently tried them and the 6.6 chevy 3/4 ton trucks on the Ike pulling 16000 lbs. They are supposedly doing a 6.4 Ram sometime soon, the latest one I know of was back when they still had the six speed.
ChevyFord