12' x 7' (80-82") 3 panel up to 16x8 4 panel sliding glass doors are pretty standard 4' wide panel sizes available in most pedestrian brands.

It's the stacking sliders that cost 2-3x due to multiple tracks, and/or large sf panels as the glass thickness, frame strength, wheel size & quality is all more as well as install time & usually on site assembly (glazing) required of the panels all adds up to more expensive.

I guess I would say in the $10K range - is what I mean as affordable. I don't need a 20' opening. But 12' - 15' would be the type of opening I'd be looking for. Is there a recommended brand you'd suggest?

We have a 12' x 8' Marvin clad door that was less than $6k 5 years ago, so it could be less than $10k now. We've been very happy with it. We have a covered porch roof over it so we're able to use the optional lower threshold.

Depending on your location, local glazing companies may offer the best value. For my house, I initially looked at national brands at big box stores, but a local company was able to offer higher quality at a better price.

When do you need them? I think may be you can import aluminum folding doors from us.

You can tell me the precise dimension of your door.

I would also recommend checking what local companies have to offer. I am sorry about what happened to your house. What you have in mind sounds great, would love to see some photos once you finish the whole project!