Towing capacity is a fallacy. Whatever truck you're buying, look at the axle capacity, and the payload rating. Typically the 8 speed is coming in a more upscale optioned truck, and more options means less payload.
My half ton 5.7 was rated at 11000 lbs towing (that's based on rear axle ratio) but could only carry 1200 lbs. Take away 400 lbs for passengers, 500 lbs for hitch weight and that didn't leave much for luggage / cargo. Oh it carried more than it's rating, and did so without complaint other than scrubbing the rear tires, but it was an unrealistic expectation to continue down that road.
The new 3/4 ton has 3300 lbs payload rating, it doesn't move more than an inch when I drop my trailer on the ball, even with the bed loaded with all sorts of cargo.
If you haven't bought the truck yet, beat your dealer up a little, they can get you a 3/4 ton for the same price as a 1/2 ton, you just have to give up some bells and whistles... more truck, less glitter.
2013 KZ Sportsmen Classic 200, 20 ft TT
2020 RAM 1500, 5.7 4x4, 8 speed