Create a website secure area with file repository and search

Hello, This project is to create a secure area on my website, behind a login screen with 3 webpages. One of these webpages is a long list of 4500+ PDF, audio and video files with a show/hide menu. The secure area will include a search engine for these files, for example using Elasticsearch or Zoomsearch, plus a dropbox-like file repository to upload new files and view them. This is all responsive, no Wordpress, and preferably using SSO. I'd like to use open source only, and the priority is to be fast on shared hosting, and easy for me to use and update eg the file indexing. I currently have a secure area, but the current setup uses Usercake for the secure area and Fluid Dynamics for the search engine. Both of these installations are obsolete, which is the reason for the change. However, this also means that I have the content of the 3 webpages, the file list, and the design of the header, so there is minimal-to-no web design work. There's only 1 difference compared to the current setup - the addition of a repository that others can upload files to, and view them, for example using Nextcloud, Pydio cells, Owncloud, Peergos, etc. I don't know what software is best, and how to integrate them, so please advise me on your recommended solution. I prefer a fixed price bid, and please include information on your availability, as I'd like to start this project very soon. Thanks!