A technically simple website, like kickstarter or indiegogo

The website will simply accept payments through paypal, amazon payments, google wallet, and credit cards. I would like a working skeleton of a website, which I can further flesh out in the future. This means that code is required to be well commented and documented. The design decisions regarding the code/database back end as well. This involves documenting the testability of the payment systems. Website inspirations include humblebundle and kickstarter (payment-taking websites). A list of payments/contributions are stored against projects. The payment details can either be stored for later charging (like kickstarter) OR charged immediately, depending on the project's settings. In the latter case, the payment details still needs to be listable for the whole project. A username/password will be required to access the contribution listing of each project. Therefore, each new project will need to ask for a new username and password.