A Notes db works well for this type of repository and links easily to other libraries, web pages and can be embedded. Sharepoint would also work for you but I’m not as versed on its full capabilities.
This is exactly the type of job that Lotus Notes was designed for. There is no combination of other products that will accomplish the task as easily as Notes and with the most security. Microsoft has been trying to build a Notes killer for 10 years and they still haven’t done it. I know, I’m trying build a replacement using all of the Microsoft tools and it’s going to take a much longer time, cost way more, and not do as much.