Any non-custodial wallet will work tbh. The best wallet would be a desktop one that is solely used for your chosen network and gives you total control over your funds, like Electrum (electrum.org) for bitcoin. Ideally it would also let you connect to your own node, although that could be used to trace transaction origins. Your wallet is only as private as you are :3
It sounds overcomplicated, is there really a need for the blockchain aspect? Could the same security be provided by a simpler method (like how keybase has their identity proofs?) but better to have it and not need it than need it and not have it ig