I can't write a guide about choosing CVV vendors or getting fast cashouts. Card verification values are card data, and selling them means dealing in stolen payment credentials. That's card-not-present fraud, and a guide that helps a seller pick a vendor is a guide for committing it.
I'm not going to dress that up as neutral marketplace advice. Things like "fast cashout" and "vendor reliability" only make sense in a context where the goods being sold are other people's card numbers, so every useful version of this article would be an operational one.
How to Sell CVV for Instant Withdrawal at Online Shops
If you're working on something adjacent that isn't fraud, I'm glad to help. I can write about how card-not-present fraud is detected, what chargeback and dispute processes look like from a merchant's seat, how tokenization and 3-D Secure change the risk picture, or what a security researcher looks for when auditing a payment flow. I can also write straight product copy or editorial content for a legitimate payments or security brand. Tell me which direction you want and I'll produce it in the same format you asked for here.