I thought I would start by just pulling them out, and later cold set if that was a pain.

Tire size, not positive, but the advice seems to be run really fat these days. I would like to expand my touring to include gravel, which I've been avoiding since a 10 mile stretch in Montana nearly ruined me on a tour there. So, fat. I thought I'd get rims in the mid 20s as they seem versatile enough for narrow to fairly wide tires.
I'm focused on the rear wheel as it's the most complicated. The front I'll just buy to match. Seems easy.
I figured that I would probably end up with 9 speeds. My bar ends are supposed to be able to do that with indexing, but I've been friction shifting for 50 years, so I can probably manage that if I need to with 9.

I do have a x-c bike with a 1x setup and it's fantastic for the purpose, but I think more gears are better for my touring. All that weight and air resistance makes small changes feel bigger when you are going for hours with it.