is that it can only scan child-porn manga.

If you need your solution to be cheap and customizable, you might think about picking up an NSLU2 and a few 1TB HDDs.

http://en.wikipedia.org/wiki/NSLU2 http://www.nslu2-linux.org/wiki/

It's basically a usb-to-ethernet bridge which you can flash with customized firmware or a trimmed-down debian install. Plenty of people use it as a lightweight server for FTP, NTP, DAAP, etc.