Custom Payment gateway for website

We need a custom made payment gateway that will be integrated with our current website. The payment system we like to develop to get part payment from individual who are part of a big order. Example School students, Club members etc. In current system the school collect the jersey cost from each students and pay us in bulk for at a time. In this new system, we will collect the payment from each student by our new online gate way. Now the only difficulty here is sorting out the people who has paid and who hasn't. The software should do the following 1. We need to create a new account for each customer. The account user will be the email of the customer and password a unique 4-6 digit number. Once Customer log in there he should be able to see the list ( alphabetical) of names who has made the payment ( First and Last name), payment amount(we can also fix it for each customer), payment date. Total payment if we can show there will be also good. 2. When students logo in they need to use only the unique 4-6 digit code, same as customer uses. Then they will be asked to fill in mandatory fields First and Last name, payment amount ( if we couldn't pre fixed it for them) & email to proceed to the payment. These names and dates here the system should extract and list them in the customer account page. 3. Customer will be given 2 options credit card using Eway or Direct bank transfer. Eway payment will attract 2% surcharge. 4. Customer should receive an auto receipt to their email and a copy should display on the screen. Here is an example of similar system [login to view URL] That's it. If you have any question please send me a message. No hurry in this project. It can be finished in 4-6 weeks. Thanks