The advice ronheater gave you is very good. Read and reread that and then ask questions if need be.
You can't go by tow ratings. Most half ton trucks run out of payload well before they hit the oem tow ratings.
The 2015 Silverado i had, had 1704 lbs of payload. With my wife and two kids in that truck, loaded for camping with all the gear, with my tt, which is 6k gvwr, i only had a few hunderd lbs of payload left. I'd bet that load i had on (week camping trip) would have had both the ram your looking at, and your current tundra over loaded, (payload).
Imo a 7k gross tt is pushing the upper limits of 1/2 ton towing. Some of the campers we have been looking at are 7-7500 gvwr and over 29' long and you can see what i upgraded to in December.
Just my .02, i do like more margin than most. I agree with 69gwc, better to get a new express or tradesman for similar money than a 3 yr old truck with 50k. I love my tradesman, but i am a simple country hick. Lol. Good luck.
