Cash back website back-end needed

I need a backend for a cashback website using PHP and mySQL (like [login to view URL]) except much simpler. I will be using LinkShare as my sole affiliate provider. Here is what I need: Simple but secure "account feature". Each account needs a username, password, paypal e-mail address, and an "ID". This ID is how we will keep track of which user completed an affiliate offer. In order to track which user completed an offer we will be using LinkShare's "signature" which allows us to pass an optional value in the affiliate URL. This will be the unique ID attached to each account. Once a user completes a sale/offer on LinkShare it will show up in a LinkShare report with their ID attached to it. So after the user logs in I need a script that changes all of the links to include their unique ID. Finally if possible I want a script that takes a report from LinkShare and automatically syncs with the DB on my cashback website so that I don't have to manually update the accounts. Please note this is not a complete website design! I am NOT looking for any design just the back end, that being said all you need to include are the following: A Login page A Register page Once the user logs in needs to redirect to a page that includes the hyperlinks that are dynamically customized for the account. An "account manager" page where the user can view/update their e-mail. These pages just need to be barebones forms and hyperlinks no need for design.