are you up for 40 hours of driving rather than at least that many of rust repair?
https://67-72chevytrucks.com/vboard/...78#post9311478
big back window though.
From what you show of your cab there is nothing that can't be fixed. But it is crusty enough that once you start poking around you will find more to fix. From this distant POV I'd say it is possible your cab is best suited for a patina or primer ride...fix the essential structural problems treat the rest with wax based rust inhibitor and finish getting the truck drivable and on the road.
If you want a shiny well painted truck your cab may be an uphill struggle - and good learning experience for body work and welding if that is what you want. But you will either put many hours into learning to make panels or many dollars into buying patch panels.
There is a risk to looking too closely at the cab you have. As it sits it has value (in Canada at least), but if you poke holes in or cut out all the rust and then abandon it it will have little value.