Relational Customer / Client CRM Database Built. Web Portal Front End / backend SQL.

I have very rough outline in excel as to some of the initial tables, indexes as well as an excel file laying out how the tables relate to one another. Some of the functions of the interface/database listed below. Requirements of front end/back end: Will run the sql dB and front end on an in house sql / web server with the ability in the future to move to aws or cloud. Admin interface: Import txt,csv,xls, comma delimited format files as well as import files from folders either manually or on a schedule. The files contain lists of users and user info that needs to be (if not already in dB) added to main database and assigned unique ID. There will be about 20 different types of either text files, csv, comma delimited format that we use on a daily basis. Some are just flat text files with 5,000 single line names going down a row. Some text files may have a single name in each file and nothing else but there may be 30k text files. Would need the ability from the web interface to select the type of file in question and select a predefined location of the folder where the files are located and import them to a specific table. Need to be able to generate text files and or excel files based off selectable data in the database. Example of report and/or export of data to text file would be: there will be a username table for each client that may hold 50k names in a column for each client. Need to be able to compare how many of the same