Can't decide between 5.0, 6.2 or 6.7

Hey all, ive been doing some heavy research into the ford trucks of the mid to late 2010s. Im looking for a new-to-me work truck, im not doing serious regular towing, but i do tow on occasion. Ive got a big family, 3 kids, and some property up north (i live in south ontario) so i want it to be big enough to fit everyone for the long trips and be able to handle the logging roads i will have to take. But it will mostly be used for work, daily driving, hauling lumber, tools and whatever other materials i might need.

Im looking for reliability, i understand the 5.0 will handle just about everything i thorw at it. But i like the 250s and 350s for their ground clearance, overall power and better capabilities. So ive been looking into the 2015-16 models with either the 6.2 or 6.7. From what I've read the 6R140 is a solid transmission, and both engines are praised for their longevity and "bulletproof" nature. I know the 6.2 is much worse on gas than the 6.7, but from what ive read, the only main issue people seem to have with them is the 16 sparkies it needs every 60k. With the diesel ive heard more horror stories about expensive maintenance and more things that can potentially go wrong. I love diesel trucks, but im not wanting it to be in a shop for long periods, which would put me out of a work truck.

Im looking in the $30,000 range, which puts me in a 6.2 with around 120-170k kms or a diesel with 180-250k kms. Is there anything i should worry about at those kms? Any other issues to think about? Any other years that you would recommend? Any and all advice is welcome and appreciated. Cheers