I haven't worked on Freelancer for a while now, but only because I have been busy with word-of-mouth work following on from previous systems I've built.
The software you're looking for is exactly what I do; Web-based application running on a highly resilient platform.
I'd split the software into four key parts;
- An API that handles the business logic and has sole access to the database, ensuring security through pre-defined queries.
- A Management interface, allowing your staff to create, review and amend accounts.
- A Provider interface, allowing restricted access to the data - enough to confirm insurance coverage and request a claim be started.
- A Claims Team interface, allowing complete access to the data.
I can also host this for you when it's complete should you need, but we can discuss that later should you need.
I'd love to discuss your requirements further assuming you're happy with the high-level proposal.