Hi,
Unfortunately there is no such a option in current version. But we will consider the "e-goods" support in some of the future versions.

You can try to do something like this:
You can create documents for each PDF file with description, etc. Underneath you can upload the PDF file to be a CMS.File and mark it as a product. Set the file to require authentication. This means that the customer must be registered and assigned to appropriate role. In the e-mail message after purchase you can send a link to this file and access credentials. After this the customer will be able to download the PDF.

I hope my brief description makes sense.

Best Regards,
Juraj Ondrus