I want to build a media/backup/etc... server

[LeperousDust]

Oh i get that but when i'm playing about with a Tb of data, i can't back everything up, its not practical, i'd rather just make sure i'm safe(ish) from hard drive failure. Yes accidental deletion and the like will be my responsibility

I'd love to buy a cheap PCI-e raid card, but i REALLY don't want to have top spend any money on this, and the mobo doesn't support PCI-e (Asus P4 DEluxe board can't remember the exact name)
What would you recommend then, if i were to go down the linux route?
Updated list of musts i guess:
I wan't to be able to access the drives as one drive from all pc's on our network.
It would be good if it were a print server
But also be used to play media directly on a TV (it's sat behind and havea s-video out which'll do).
Able to remotely log in and fix things as it's only monitor will be a TV and they're just no practical to use...