I normally get the UltraPro cases from my LCS because they are cheaper there but you can get it from here too: https://www.amazon.com/dp/B01EK6OXFM/ref=cm_sw_r_cp_apa_glc_fabc_NHNVPNE1W72KXJXQZCS1?_encoding=UTF8&psc=1

I don't know where else you can get the clear backboards but this is who makes them.

https://imgur.com/a/BSTMlF9

I use this one; https://www.amazon.com/Current-Comic-Touch-Magnetic-Holder/dp/B01EK6OXFM/ref=sr_1_8?crid=24ZW09KKS9WXS&dchild=1&keywords=ultra+pro+hard+case&qid=1623278782&sprefix=Ultra+pro+hard%2Caps%2C264&sr=8-8

It's super sturdy, UV protected, has magnetic closures that allows for easy opening and placing another book in. I use it more as a stand up frame in a bookcase, but I'm sure it'll look nice on a wall as well

I personally think this is a great way to hang slabs

And this for displaying raw comics.

Then there's also these mounts.