Hi, my name is Giovanni and I'm a computer programmer. I understand that you would like a payment system that involves credit/visa cards so that users can buy an account once they pay the required amount. I will be very happy to assist you with building such gateway and we can use Paypal since it supports credit/visa cards or we can use Stripe which is a better option to accept credit cards without a merchant account or enormous fees and you will have your own system. Once the required amount is paid, your website will then create the user or deliver his resources. If this is what you intended, please feel free to contact me so we can work on it together. Thanks!