Multi-function devices have the ability to print, copy, scan, and fax. Printers can only print.
Department IDs (user codes) are used to restrict access to the device and keep a record of the user's usage.
Do you have an idea of how many prints will go through the device? This can be a rough estimate.
Are you looking to do specialty printing like booklets, small posters, flyers, envelope printing, etc.? Or, do you plan to use it for standard document printing?