I don't know where you would find the binders that are the same material as the MZ ones, but I will share the binder that I use for all of my mini-set... I use the MZ ones for main sets, and this one https://www.amazon.com/gp/product/B081W1L6FL/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1 for mini-sets. Hope you find something!
Not sure if these works but:
https://www.cardboardgold.com/cucobotoc.html
And maybe these:
Comic Mount Comic Book Frame, Wall Mount Shelf Stand, Invisible and Adjustable, 1 Pack https://www.amazon.com/dp/B00GP1HJQG/ref=cm_sw_r_cp_api_glt_fabc_HT181EPTYPAC10YN5E6N?_encoding=UTF8&psc=1
Same here! So funny you asked because I had this same problem for metazoo comics a few days ago. I ended up just buying a small storage filer/binder type thing and a regular bin from Walmart (they do have actual comic book bins as well if you Google it) to put in. Works great for me, here's the links:
File Organizer:
Accordian File Organizer, ActFaith 12 Pockets Expanding File Folder with Cover, Portable Document Organizer, Desktop Plastic Receipt Paper Filing Folders for Office/Business/School https://www.amazon.com/dp/B08T95QS2F/ref=cm_sw_r_apan_glt_fabc_D5ARGHD7C11T97QW5N5J?_encoding=UTF8&psc=1
Bin:
Of course. This one is the same brand I can’t find the zipper one Vault X Binder - 12 Pocket Trading Card Album Folder - 480 Side Loading Pocket Binder for TCG https://www.amazon.com/dp/B07F84DM9M/ref=cm_sw_r_cp_api_glt_fabc_0M0JQBYS4WMMJFE00V90?_encoding=UTF8&psc=1