File Management Solution for WordPress

I have Googled and found dead ends. So, I’ll come here and see if anyone has an idea:

I’ve been asked to create a super simple site based off WordPress. The entire point of the site is to allow financial clients to upload documentation into their own private directory – ALL on the Front End.

I’m making the site for a friend as a favor and I don’t want to use a paid service like Gravity Forms, even though that is exactly what I need. I know, I know, but I’m trying to help a friend here, not give him a new cost to take on.

I’ve tried wp-FileManager and WP-Filebase but neither seem to do what I’m looking for…

He’ll create a username and password for his clients in the Back End himself and then email them the details. He wants them to goto the site, login and be able to upload files, download important documents he uploads himself and he would like it so each user can only see their own files, he sees all.

ANY ideas? Again, it all needs to be on the Front End for the clients – HE can use the WP Dashboard for his use.