I'm not really sure what your looking for, but we use Fortis from Westbrook Technologies for our doc storage.
It's performed well, very flexible, and uses MSSQL for the data storage. Because of that, we've been able to integrate our ERP system to populate additional data fields, so the user simply enters one piece of info (truck number, po number, employee number), and we populate a ton of other fields. This allows for some power searches within the product.
We use it for just about everything, pictures, faxes (direct input from a fax server), scanners, spreadsheets, PDF's.