I'm looking for a way to allow a group of users to upload documents which are then locked so only a small group of users (i.e.management) can make changes. The files need to be uploaded with Metadata and i've not find a way to do it purely with access permissions. any suggestions or ideas?
I don't have the required reputation to comment. My answer: With SharePoint Designer Workflows, you have the option of using Impersonation Step. Use Impersonation Step to modify the permission at the document level. Create a group which will contain the users from management. Using Impersonation, remove all the permissions associated to the document and add only the newly created group.