Customized Shopify File Management App

I'm looking for a custom Shopify app to be made that meets the following requirements: I need a file management system that users require a log-in to access (if they're logged in to Shopify, that should suffice). Essentially, customers need to submit a request to the file system for a specific file, and I need to be able to reply with the file for the customer. They will also then need to reply to my correspondence, either with comments, notes, or by uploading additional files. I also need to have a database of files that customers can download, however they need to have "credits" available on their account (ideally purchased from the Shopify store itself) to be able to access these files. When the customer has credits, they can download the file, however they need to enter some specific details and the file needs to pass through an API to be coded with their specific details. In a perfect world, the customer will be able to enter their details on their user profile - and we would like it so that they can only edit them once to fix a mistake, otherwise they need to request a manual change to be made. The transcoding API will then pull this data to transcode the files at the time of purchase/download, rather than requesting it every time. Additionally, customers should be able to see how many credits they have available in their user profile, so that they know if they can use them to purchase a file, or if they need more. These options are only applicable to a small percentage of our customers - perhaps 1 in every 50 customers will need to have access to this system and/or the optional fields in their profile and the counter for credits. My initial thought is that when they first purchase credits, these options become available to them. Customers also need to be notified by email when a response to their "file request" has been added to the system, and there should also be a "traffic light" indicator as to whether they're waiting for us to supply a file, or if we're waiting on them to supply further information or additional files from the customer. When the whole process is complete, either the customer, or someone from our admin team needs to have the ability to mark the "custom file request" as closed.