Password Locked Reports with Single Login?

Hi One of our clients is running a pathology lab and they need a solution for their reports download system,
it needs to have the following features

1. The reports need to be locked ID and Password.
2. Customers should not have to register with their website.
3. The customer should get an option to e-mail the report from the lab website to their consulting doctor.

Any easy baked solution? For this?
The client is on the budget.
Thanks.