are you able to recommend a pockets which perhaps in a position to do somthing like this?

None or any.

I’d simply use a spreadsheet to maintain an inventory of names and quantities (BTC equal of $20 at date of qualification)

If I used to be nervous about alternate charge fluctuations I’d purchase sufficient BTC on the finish of per week or month to cowl the client rewards that qualifies in that interval. I’d use any single-user pockets and never use the pockets to correlate quantities to clients.

When a buyer wished to “withdraw” I’d simply use that pockets to ship the handle the client gave me a BTC quantity famous within the spreadsheet.

For 600 x $20 ($12,000) I would not look forward to finding an current complete answer that meets all my wants and which may be bought/rented and built-in into my current techniques for a lot lower than that quantity.