Looking for plug-in to offer personalized account info/files/videos… possible?

I’m a freelance web designer who is making the move from more traditional static sites to WordPress. I just received an inquiry for a new job and am trying to decide if this is above me or if I need to consult with some others. The problem is that I don’t know what to search for yet to determine if I can do the job.

The client definitely wants a WP site. She is looking to use it as a means to handle some of her own CMS.

The main issue is that she wants to create an online resource where clients would be able to create an account and access their files online. She offers a service for purchase that is made up of different levels. Within each level there are forms and audio files that the client should be able to access online. Additionally, there needs to be some sort of electronic journal functionality within the account as well. The client would need to be able to document various steps along the way and be able to access them later for review, editing, or deletion.

I’m sure all of this functionality exists, I’m just not sure what terms I should be searching for. This is a rough analogy, but the end result would be similar to the online tax programs like HR Block where you can sign in to your account, fill out some forms, go back and edit, save your work, come back to later, watch a help video, etc.

I’m grateful for any advice/direction that can be provided! Thank you in advance and I’m looking forward to the genius answers you all can provide.

-Adam