Cost Per Action (CPA) Link Exchange System

Hello, Looking for an experienced programming team / individual to build a simple Cost Per Action (CPA) link exchange system. The main idea of the website is to allow people to post links from their Pay Per Download (PPD) site of choice and allow other people within the system to access that link and complete the attached action required (usually in the form of a survey). If the user completes the survey successfully , then they should gain a point within their account. The point is only given after the system confirms that they completed the CPA. This can be done by requiring the user to input a special code (that is only known once the CPA is completed - by opening a zip with a text files containing the code or something). If the user inputs the wrong code, then the point will not be granted. When people add links to be exchanged, our system will provide the random code that they should put in their file (that will be revealed once the CPA is completed). So, the system will know and be able to track and manage the different codes to confirm that CPA offers were in fact completed. So a user can upload PPD links to exchange with others and also access PPD links that other users have posted. Note that a user should not be able to complete the CPA on the same exchanged link twice. The system works on a point basis and certain restrictions should be enforced based on point counts. In order to post a PPD link (for others to access), the user would need 3 points. They can either download other PPD files and get their point count up, or they could purchase a premium link. A premium link purchase would not require them to have 3 points available in their account. They could just pay $3 and bypass that requirements. This would require PayPal IPN implementation. There should be a randomized system to determine how many download slots each submitted link is allowed. Free links should get a random number between 1 and 10 and premium links should get a random number between 10 and 20. Once a particular link reaches its max download slot, it should be retired from the system so that no one can access them. When a user accesses the PPD link, it should not be embedded in our system. It should open in a new page. Remember, the important thing is for the download code that the user inputs to match what's in our system. This system will not have many pages, I imagine the folllowing: Home How It Works Contact Register Login My Dashboard My Links My Downloads Change Password etc We are looking for something VERY simple that gets the job done effectively. Send us a PM and let us know your ideas for this.