Attach Image(s) to Open PO

I have a client who would like the ability to attach various documents (such as drawings, technical specifications, etc.) to an open PO. They would need the ability to open the docs directly from each PO. I have not yet explored the exact details as far as whether the documents need to remain attached to the PO in post... but I wanted to throw it out there to see if anyone had any thoughts.

Thanks!
Alyssa