I'm looking for an elegant way to solve the following problem:

My development team uses Dropbox for sharing documents amongst our immediate group. We'd like to put some of those documents into a SharePoint repository for the larger group to be able to access, as granting Dropbox access to the group at large is not ideal. However, we'd like to continue to be able to propagate changes to the SharePoint site simply by updating the files in Dropbox on our local client machines, and also vice versa - users granted access on SharePoint that update files in that workspace should be able to save their files and the changes should appear automatically on our client PC's.

I've already done the organization of the folders so that in Dropbox, there exists a SharePoint folder that looks something like this:

SharePoint
----Team
--------Restricted Access Folders
----Organization
--------Open Access Folders

The Dropbox master account and the SharePoint master account are both set up on my file server. Unfortunately, Dropbox doesn't seem to allow syncing of folders anywhere above the \Dropbox\ part of the file system's hierarchy - or all I would have to do is find where the Sharepoint repository is maintained locally, and I'd be golden. So it seems I have to do some sort of 2-way synchronization between the Dropbox folder on the file server and the SharePoint folder on the file server. I messed around with Microsoft SyncToy, but it seems to be lacking in the area of real-time updating - and as much as I love rsync, I've had nothing but bad luck with it on Windows, and again, it has to be kicked off manually or through Task Scheduler - and I just have a feeling if I go down that route, it's only a matter of time before I get conflicts all over the place in either Dropbox, SharePoint, or both. I really want something that's going to watch both folders, and when one item changes, the other automatically updates in "real-time".

It's quite possible I'm going down the entirely wrong route, which is why I'm asking the question. For simplicity's sake, I'll restate the goal: To be able to update Dropbox and have it viewable on the SharePoint site, or to update the SharePoint site and have it viewable in Dropbox. And since I'm a SharePoint noob, I'll also need help hiding the "Team" subfolder from everyone not in a specific group in AD.