There is no easy answer to truck choices.
New models are nice, but costly.
I had 7,3 diesels and even the engines were reliable, still sensors, alternators, washer tanks and other small stuff on aging truck did cost some money.
Bought 2007 with 6l knowing the engine is trouble, but paid 45% of KBB for it and I am DIY so I am fixing it myself.
So far after oil cooler exchange the truck gives me no trouble and delivers 16 mpg @70mph with camper shell, or 10 mpg with my big camper when going to Sierra.
Flatbed bed if few inches higher than regular bed, so when you have tall camper, that might be an issue.
My Fleetwood camper put on utility bed made 13' tall.
