VPN vs FTP

I am trying to decided if I should setup a VPN or FTP server for our hospital server. Our inhouse server is going to need to be accessed by our transcriptionst for dictation, one of our software providers accesses the server now by dialup to make changes in his software, and we are looking at going to digital xray where the radiologist will need to access images stored on the server. I am trying to decide if I should setup a VPN or FTP server for this access to the server. Which has the most security – what about implementation – I need some expert advise. We have T1 connectivity.