Hello there - thank you for your response. As it turns out, I had arrived at your solution three as the best for my application and thank you for the validation that I wasn't missing a better alternative. Portfolios I had considered but discarded, and the security option I didn't know about, but now do and will surely use at another time thanks.
One other question for you: when my client reviewed the document on his laptop, the PDF opened at 144%, the screen width which was readable. When he clicked on the links, however, the linked document opened at 70%, too small to read. Is it possible to control at what size the linked document(s) opens?