Asterisk a2billing and Joomla integration

Hello, We are currently building a website that will allow customers to sign up and buy PIN number online. The front end has been developed in Joomla with multiple languages using joomfish extension. We currently using a2billing and need to integrated back end with it. We have developed graphics and looks for the back end. Basically we need to integrate Joomla with the back end graphics along with a2billing 1.7. The reason we would like to use joomla is to be able to change content easily in future if need arises. Requirements. 1. Must have a very good knowledge of a2billing from version 1.4 and up. 2. Must have a very good knowledge with joomla and database integration. 3. Must know PHP AJAX CSS and table-less design for a faster page loads 4. Optimize Joomla to handle hight load if arrises. 5. Must know asterisk and custom IVR logic. ToDo. 1. Registration Page from Joomla - Customer need to register to get access for the back end. 2. Back end will have following. My Account, Pinless Dialing, Speed Dial, Buy Credit, Promotional Codes. 3. Must be able to accepted following, Credit Cards with [login to view URL] or Paypal. Also integrate SSL certificate for the site. 4. Integration with a2billing needs to be done in the way without braking it or customizing it. So in future updates we would like to update a2biling and be able to work with it and still have all the features. Maybe write some kind of API's and integrate it with a2billing. 5. Hide the web server behind proxy for security. 6. Joomla Front End - we need to create a page to search for the calling rates by the Rates or Minutes. 7. Joomla Front End - needs a page for access numbers to be able to search in the following: Calling from > Country > City and show the result. (upon completion top part additional work) 8. When balance gets to close to $1 and customer is on the phone talking we would like to recharge his account while he is on the phone play IVR that his account is refilled. Integrate IVR to be able to accept credit cards over the phone for the existing customers. 9. Integrate Asterisk with a2billing for the customer service calls. When Person calls and get into the que IVR ask for his pin number or registered phone number and pull his information on the customer service computer when customer service pick up the phone. 10. Create Custom Reporting for a2biling and graphs. 11. Integrate sms GW to send out SMS messages. __________________________________________________________ When bidding please include past work that related to this project.