Convert an existing Web/SQL Application to .Net

We have developed a full-scale web-based SQL application for managing Property Tax Assessments. The project is currently running in Alpha Anywhere, a RAD front-end using Javascript and Server-Side scripts. We would like to convert the project to an Angular or React.js based .Net Core or .Net application. The project consists of several tables, links to stored procedures, file-based photos and sketches, and will need to run on client hosted IIS servers in Windows 10 or Windows Server. All data is in SQL Server 2017 Express. We will need user authentication and granular security for data entry, administrators, and view only users. We may also want to develop a stand-alone mobile interface that provides off-line work and data synchronization upon restoration of internet connectivity. All applications will run at individual client sites behind VPNs and we will need an option to perform updates to software on all deployed client sites. Reports should be produced as PDF documents that can be printed or saved. We also require the options to export to CSV, Excel, and Fixed-length files based on a number of search criteria.