Would FreeNAS allow him to torrent though? I was under the impression that NAS was intended just for storage rather than a more complex server.
Also if you are willing to work with windows, the new version of Microsoft Home Server is in Beta and seems to be pretty stable. Even the retail version of Home Server is less than $100. I only mention this as I've heard it's fairly easy to use for beginners and being based on Windows can run Window's apps if needed.