Autosync a folder with PDF for iPad/iPhone

Is there a way to autosync a folder with iPad?

We'll have a shared PDF folder in our company, and what we need is the iPad to autosync with that folder, because the PDF files can change from day to day. So far we have to choose the specific file on the iPad and delete it, and then again choose the new file, which has been updatet, that's a bit difficualt. The problem is that we are not online with the iPads, and its not possible to be so. So using DropBox or similiar is not possible.

This solution is possible with music, cant understand why is not possible with PDF. Our PDF's are in different folder, so we need a app/solution which makes is possible to choose folders, and not files.

Hope some can help me:-)