Custom IPN Created (Send links to verified user, allow user to retrieve)

I would like to have a paypal ipn created that sends an email to the purchaser after the purchaser with links for their downloads and save the transaction in a database. The purchaser would also have the ability to place their email address in a form to have the links retrieved based on their paypal address(retrieval period is limited to 24 hours). Purchase flow: Buy now button is selected The purchaser is then prompted to pay via paypal The purchaser is then automatically redirected to links created, so they can complete their download. IPN will send email to purchaser with links and small message Small input form will be placed on the website to allow the user to retrieve their links within a 24 hour time period.