See if there is anything useful here:
- https://old.reddit.com/r/Masks4All/comments/sqxvvl/earloop_mask_recommendationalternative_to
- https://old.reddit.com/r/Masks4All/comments/ssdb39/best_n95kf94_mask_for_really_big_faces/
Unfortunately those seem to be earloop style masks though.
The 3M 6200 (elastomeric half facepiece respirator) is available in different sizes. I have the medium and it fits me ok, so you might see about a large. This type of mask makes you look like Darth Vader so I tend to save it for special occasions.
I’ve had pretty bad luck with the Gerson 3230 since they fall apart rather rapidly. I bought a box of 50 and still have a few left, so if you want, I can probably send you a couple to try.
I do like the 3M Aura 9205 except for the rubber straps, but again, they are sized ok for me and might be too small for you.
I used proxmox and have played a little with nix and guix, but simplest is just use debian, put /home on a separate logical partition from the system partition so you can reinstall the system without clobbering user files, and as people keep saying, backup early and often.