How about a enclosure with 3 trays with hdds.

Backup daily, one offsite and one in transit so to speak.

Shutdown , swap tray in the morning and with the one off site, you would not lose much if disaster struck.

SyncToy
should do the trick you want.
http://www.microsoft.com/windowsxp/u...o/synctoy.mspx

If you want to set up a dedicated file server, I am using a pc with XP, AMD 2500 cpu and a GB of ram. Works nicely..