Development of a website for international calls for end users :

PROJECT : Developing a website for international calls for our customers : After creating an account and prepay with paypal or moneybookers, a customer will receive a personal code (long pin code) that allow him to call either from the website (better if it is done with Wordpress) through a web phone interface or either using a local number to dial (for example from his mobile phone), following the instructions on the phone. The system will be using A2billing and Asterisk, which we have already installed on our server, but A2billing need to be properly configured and eventually modified. We also want our users to be able to check from the website, credit, cdrs, history of calls etc, payments, download invoices, open tickets etc. Everything must be extremely secure: calls must stop as soon as the calculated available credit finishes. Payments and registrations. Requirements: High skills and experience with a2billing and asterisk, experience with Wordpress will be very appreciated.