If I were in your shoes, from the impression I am getting by your posts, I have some advice.
I do not like 12 valve cummins trucks. The 12 valve motor in stock form is not my kind of motor. They have problems they should not have, think death pin, and cracked cylinder heads. I am not sure if the cracked cylinder head stuff is over the internet, but I know a close friend who had cylinder head woes. I also find because they are 'popular' parts pricing is not where it should be. Anyone every price a p-pump out, wow, just wow. I also know the nv4500 may not be terribly strong.
Now, moving on, my vehicle recommendation to you, based on what I am getting off your posts, I would recommend, a superduty with a gas motor. I think a 05 to 07 year range will be your sweet spot. The benefit of the torqueshift over the e4 in the gas motor is worth the extra money they may command over the 99-04 super duty trucks. I don't have to get in depth with the choice, but people here will understand. A mod 5.4 has its problems, but its relatively proven, and does its job.
A runner up choice for me to recommend to you would be a hemi powered dodge 2/3500 single wheel truck, all the things that make me recommend the super duty apply to this truck as well.
Third runner up, Chevy 2500/3500 with an small block. This only gets pushed behind the dodge because I dont like there IFS. If these had solid front, it would be a way better choice, but they also have there funky issues to.
I don't recommend diesels anymore, as I think they are only worth it if super heavy loads are hooked to your truck or if you run it for a living. You telling me 'occasional' hauling, these gassers will suffice. Diesels newer then 07, I would throw them ALL away. Its to nuts. I also am not a fan of how much they cost in new trucks. Why would I add $10,000 to my sticker price for something that will cost me MORE to run and maintain?