Salesforce Quote Template Auto Populate

Hi,

Inside a quote object there is a related list of Quote PDF's, when you click on the small arrow on the right of the list, you get the "Email PDF" button.

Currently, when you press this button the small window pops up with a blank email with the quote attached.

However, Id like the contents of the email to all ready be filled out with a default message and subject. The default message and subject will need to use merge fields and links too.

So when someone clicks "Email PDF", the email box pops up as normal, but is pre-filled with a template and a subject.