I would like to be able to access my usb hard drive via wifi so that I can manage a larger music/video library than I could comfortably keep on a macbook air. Is it possible to use an airport extreme or airport express to do this, plugging in the hard drive to the AE? Is it simple to set up and to manage the itunes interface (including iPhone syncing) on the computer? What is the earliest generation of the extreme or express you would recommend that would allow me do this? I would rather do this cheaply and get something off of craigslist or ebay. Thank you!