FIRST CHOICE: Any paper that is acid-free and cotton will be your top of the line choice.
SECOND CHOICE: They do offer archival papers now in acid-free that are wood pulp based.
Archival papers can be found provided by almost every brand. I feel like the choice of brands will be more of what works best with your equipment.
As a paper for Inkjet may be the wrong one for your Laser printer or vise versa.
We often use https://www.neenahpaper.com for the brand of choice.
Are you looking for deluxe papers or economical papers? Giclee (eg EPSON Stylus PRO 9900) or something like HP Indigo? HP Indigo would open up another range of nice and affordable papers, but it would limit you in sheet size.
Depending on what you want... almost any decent printing paper will work. (Horrors! The truth! Marketing be da--ed!)
Paper about 30 years ago was still commonly being treated with acids in the pulp stage. Acids speed up the oxidation of paper. People were freaking out about their beautiful pieces falling to bits in 10 years or less.
Nowadays, almost all printing papers sold in developed countries are made without acids. Alkalies are used instead: they cause fewer pollution problems and are only slightly more expensive to use.
Alkaline treatment gives the paper an expected life of 125 years. Which is exactly what "archival" paper specs were back 30 years ago.
In one sentence: Almost any good grade printing paper today (free sheet) in the developed nations (except, obviously, for newsprint, groundwood papers, and the very worst paper) is archival quality.
On the other hand, if you are nervous about my reliability or if you have to (heaven forbid) have an ANSI or ISO certification (a sure sign of over-pricing), just do this: google "ISO 9706 ream" or "ISO 11108 ream". That will get you a fist full of "certified" papers.