Concur with Grigg -- 4WD will be a LOT of trouble for something you only think you need
Drove a 2WD dually for ~20 years and only had to call for help twice. And then I learned how to drive

Lots of farm yards, back roads, trailers, etc. I think 4wd is a crutch for most people and its a lot of weight and expense to be hauling around for the two or three times in the lifetime of the truck you *might* actually need it.
Do you live on the side of a mountain? Or at the end of a logging road? Do you get to your house through a soggy cow pasture? If no, then I would question yours (or anyone's) "need" for 4WD.
My farm truck is a '00 F-450 in 2WD and it does just fine (once I put non-highway tires on it ...

) and it goes into a few barn yards to collect manure, etc.
I do have a beater F350 with 4WD and frankly, I only use the 4wd rarely and only because I'm going someplace I probably shouldn't be, and don't have a need to, or should be using the tractor ... But I agree with the statement above that off the highway, duallies get you *into* more trouble than they get you *out* of.
Just sayin'
JM