We are looking for a PHP developer to integrate an adult payment/credit card processor (zombaio, ccbill, epoch, verotel, etc) with a video website. The website (free) members should be able to upgrade their account to Premium (Paid) membership in order to have access to more features and no limitations. We only need the payment integration part (taking the member to the payment page, completing the payment, returning to the website, with his account updated to "premium", update done automatically in the database).
We don't want the standard procedure offered by adult payment processors, where they install their own scripts and generate a user/password and grant access to a folder. We need integration with our own script, our own member system and database. This will be probably done through an API with callback scripts.
Please provide examples of similar work and write which payment processor you want to integrate.