It seems you've outlined a few approaches, along with the negatives to each. It's your truck, you get to decide what to do with it.
There really isn't a good chassis to swap, the front axle on newer stuff is quite wide in comparison to the original.
Probably easier to keep original frame and suspension. Then if you desire different brakes or axle gears swap rear axle entirely and parts of the front axle to get newer brakes.
My opinion, just fix and drive for a while, less work, time, and money than what you have described, and probably just as much fun.
But I'm not keen on radically modified vehicles just so they look different for the sole purpose of looking different. I like practical modifications, ones you may not even see, that make an old truck work better as a truck.
Grigg
