Attaching files to a PDF can be accomplished in two ways, traditionally:
1) Using Acrobat as a client.
2) Adding a file attachment right to the PDF with LiveCycle Reader Extensions ES for Reader clients.
A PDF Portfolio provides nice features for assembling various content types into a PDF as well. See the attached example.
Your workflow requirements, the availability of LiveCycle Reader Extensions ES, and client base (Reader versus Acrobat) will determine what is possible for you.
Steve