PDF creation with password

My client is setting up a digital downloads shop (PDF’s) and has a requirement that after one or multiple products are purchased the PDF’s are then available for download.

He wants one or more of the following and i am just wondering if any of these are possible with any plugins or otherwise?

• Password protect the PDF (the password could be the customers email or other random password)
• Add a watermark – perhaps a logo and maybe date
• Add header and footer with some dynamic information (e.g. date, email)

Its worth noting that the customer’s PDF is wanted ideally to be created from an already existing base PDF but i see a lot of the plugins use HTML to create the PDF so could look into that possibly also

Many thanks
Malcolm