Convert wordpress plug in to joomla plug in

We have a website that sells online courses for users. As part of these courses, users can download and view PDFs. We are seeking either 1 of two things: 1. A custom written joomla component that will allow a PDF to be "stamped" with a "Downloaded by User on Date/Time" The component will be able to take an unsecure PDF and after stamping, encrypt the PDF to prevent editing. Software API that would take care of this is called Setastamp PDF We would like this integrated into a plug in that can be installed into Joomla 1.7 and ideally 1.5 2. Conversion of an existing wordpress plug in that already exists to stamp PDFs, and modification of this to run on Joomla