Welcome, and best of luck finding an option that works great for you!
You probably already know this, but NFC payment things out there eventually expire and are supposed to get replaced (it’s not like they’re permanently attached to you, right? Right?!) which makes them less than ideal for implants. This definitely hasn’t stopped determined cyborgs from getting them implanted anyway, but eventually it’ll either need to get removed or it’ll sit there inert in your body. (Well, technically you could probably still talk to the card with NFC readers after it expires, but it wouldn’t be useful for anything.) At least it sounds like you have some eager help. 
Research on getting/converting a chip that can be reprovisioned while still in the body is ongoing, and depends in part on what country you like in.