Create web based screening and reporting system that can be billed per test securely

i want to create a subscription based testing application. Accounts will log in and then also create record for each test taker in their account. Test will be between 10 and 20 questions and answered on a 1 - 5(1 i disagree, 5i agree completely). once completed, a report will be generated that will provide a quick overview of the results and also a more detailed analysis. this report must be available for printing immediately but must have identifier making available at later date if needed. I need to host this on a server remotely with many different accounts at remote locations (600+) accessing this system securely - with me having the ability to invoice each account for every unique instance the test is utilized.