what should i buy next ?

I currently have a basic Trezor and a basic Ledger, and I have two separate Bitcoin wallets with two metal seed backups. I keep them well hidden, and I also have two fake seed plates stored in a safe at home as decoys.

I’m worried about something happening to one of my hardware wallets, similar to what happened with Coldcard, so I’m thinking about splitting my Bitcoin holdings across four separate wallets instead of two.

What hardware wallets would you recommend I buy next?

I don’t want a hardware wallet with a battery because I’m a long-term Bitcoin-only holder and I barely use the wallets. They’re mainly backups, so I don’t see a need for a battery.

It’s also quite difficult to buy hardware wallets in my country, so i will let my mom buy then when she travel direct from a website.

What would you recommend as my next step