On the newer route; I will only buy another F-250 PSD, it will either be a newer 7.3 or a 6.0, and I have some questions:
Which engine is more dependable?
Which engine tolerates bio fuels better?
Which engine is more fuel efficient/can be made more fuel efficient?
Transmissions: my truck now is a ZF-5, I'd love to stick with a manny but options are usually limited, which one has the better transmissions?
-It is far and wide known, as you probably know yourself, that the 7.3 is a "more reliable" engine. The 6.0 isn't a bad engine per say, as long as it stays stock. Mods/More power = more stress on the head bolts, more soot to clog up the egr etc...you get the idea.
-7.3 will take better to alt fuels due to the lack of emissions controls and all the bs that comes along with them. Also due to the lack of emissions, the 7.3 will get better gas mileage. Throw a few mods on them like an exhaust, intake and chip it it can run much more efficiently, but the 6.0 isn't all that bad either.
-The torqshift is a better tranny than the e4od but, if you're going to buy a stick anyway you'll be in total control of what goes on with the transmission which will help it last.
It all depends on how you prioritize these things. And it kills me to say this but, from the sounds of the things you do, and if you leave the truck mostly stock you might be better off going with a 6.0. Until I die I'll swear by the 7.3(and never own a new truck in my life) but, due to the common and very expensive problems the plague the 6.0 a solid 7.3 is about the same price, if not more than a comparable 6.0. Just some food for thought... Best of luck to ya