Yes there was a reason I picked those specific years as a starting point. Doesn’t mean others are no good, but that would be my preference.
In 2014 half ton rams got the bulletproof ZF8 speed. I wouldn’t cross the street for a 6 speed Dodge 64-65-66-68 trans. If I had the choice.
Ford, 5.0 I’d go 2011 or newer. Eco would be 3rd year model so 2013 or newer.
GM, personally 3 out of 4 2014 new model 1500s left my job on a rollback and never returned due to major electrical issues. First model year problems.
And as tempting as it is, I wouldn’t get an Eco diesel, if I was not a diy guy. Just in case those were looking attractive.