ADF Scanner- need to scan various sized prints for slideshow

[andypress]

A friend and I are doing the senior slideshow for school, and while a number of the submitted images are digital, a lot are film prints. I need a relativly inexpensive adf scanner that can handle scanning numerous prints without any user intervention. I don't care if theyve been discontinued as long as I can find one on ebay, and mac compatibility would be a plus.