Small window to big window conversion. What's it take?

[N2TRUX]

I searched this forum and the FAQ section too. I can't find anything discussing converting a 67 cab from small to big window. Besides a cab swap, it looks like there are two ways to do this. Either replace the entire back half of the cab from the roof seam down, or weld in a donor panel with the big window frame.

If I had a truck with a rust free cab that has nice paint what would be the best way to get a big back window? Has anyone done this conversion? Can you direct me to posts or pics?