Just close the circle: 1. accepting payments => btc pay server, they can connect to your umbrel or other OS, can set up lighting also with breez 2. Hot wallet connected to Node = they can use your node for privacy 3. Cold wallet multisig, offline pc with tails os for electrum, or ubuntu and sparrow, and then use jade diy and/or blue wallet on phone cold wallet multisig and/or other diy solutions such as trezor diy 4. Exchanges, depending on your location 5. P2p exchanges such as bisq or in person groups