If he absolutely, positively, MUST get a gasser, then the addage is to keep the truck simple. Get the 2500, so he can keep a stick behind the V8's, and avoid the automatic tranny - chryslers one continuous long term problems.

I bought my truck with as absolutely little stuff in it as possible, while maintaining the necessities of high mileage driving, and living in the south. I have a rubber floor, plastic door panels, cloth bench seat, manual tranny, manual windows, and an aftermarket stereo.

I don't have a rattle one in 110k miles, and only one squeak in the clutch pedal linkage that will only require me to it it with some lithium grease to correct. So long as your friend follows the keep it simple rule, he should get as many miles out of the Dodge, as he did the Ford. It is my intention to keep my Dodge truck for as long as I possibly can.