* https://shop.nitrokey.com/shop/nkhs2-nitrokey-hsm-2-7
* https://www.yubico.com/product/yubihsm-2-series/yubihsm-2/
Consider buying two to have backups ((encrypted) export/import-backup/restore is supported).
Creating your own CA:
* https://docs.nitrokey.com/hsm/mac/certificate-authority
Considering using 'helper software' for running a CA:
* https://github.com/smallstep / https://smallstep.com/docs/step-ca/
* https://github.com/OpenVPN/easy-rsa
* https://github.com/FiloSottile/mkcert (good for on-one-host dev stuff)