We want to build a web-based application, where users can upload objects (photos, object profiles, some financial data) and download individualized reports (as pdf/xls) via their web-browser.
Given the data stored is very sensitive, both database security and user management should be top notch. What`s the best database technology to use?

There will be around 500 users with 80-250 objects each. The reports require some (simple) serverside calculations and will be tricky as lots of customized charts etc will be used.

Ah well.. the system has to be performant and the user-interface/reports should be "visually appealing" ;-)

Specifically I am looking for which application server and web framework to use.

Any ideas? Thanks a lot!