Adding a Directory Lister to my Theme

I have done a search but not found an answer to my question.

Basically I am building a subscription based site to access PDF files. I intend to use a plugin such as WP-Member to handle the subscription side of things.

There doesn’t seem to be any directory lister plugins for WP but I have found a good one I can adapt: Directory Lister

My question is:

Should I embded the script into a WP page and host all the files in the same directory (I can hide the WP files from the lister)?

OR

Should I host all the files and the script in a directory outside of WP and attempt to block access to it using the WP plugin?

I’m new to WP and PHP so forgive any ignorances.

Thanks