Utility report automation

I am designing a system to collect data from a water utility company at the water well. I will have several devices that will send data through rs485 connections and then to the web. I need assistance in the form of advice detailing the requirements to get the data from the site to a sql database. I also want a website that will have logins to pull the data from the database to a nice gui where it can be viewed and printed. I need a way to customize the gui to suite different companies. I want to put their company name and logo on top of the page when they login. Each company may have several employees who need to login and print or view the data.