Code needed - Paypal IPN integration into website

Hello friends, I need to send individual PDF files to customer after they make a payment on my website. Payment trough paypal will be notified through IPN via paypal. From there, a template e mail (which I can customize) would be sent to my buyer. E mail would have PDF (s) attached. Each PDF is different. Depending on the purchase it might be 1, 3, 5 or 10 different barcoded PDF. Once barcoded PDFis sent, it cannot be used again and deleted from site or some system set up where I know which PDFs I can delete because they have been set up. This should be an automatic process which happens within 1-2 minutes of purchase. There are several companies which do this for FREE. This is like e junkie. Wix also is able to do this if the purchase is through your wix website (store). However, I need something just slightly different. I need the same exact thing done, except my digital PDF is not the same for every purchase. It is differnt for each purchase. I can do this by creating several different bttons on my website (one for each PDF) but I want to be able to use one button so customer can make purchase and then be sent different PDF with templated message to purchasers Paypal e mail with thank you message and attached PDF. Thank you for taking time to read my project. I made this as detailed as possible so the quoted price will be accurate. I will go with the LOWEST BIDDER as long as they have over 100 reviews and a 4.8 star rating. thank you!