If you want to simplify... AND you are behind a firewalled router, you can get just about any external drive that has a network port on it. You attach it to your router with a network cable, configure it a little, and you're all set. DO make sure that the the drives ethernet port is 1Gb/s.

You should be able to get 1TB for under 300$.

If you want redudancy (RAID-1), you'll need a SAN with a bit more brains. I've used the Netgear SC101 without any problems. The only drawback is that it's not Linux compatible.

I'm sure there's a way to use 2 networked external drives and let one be the other's backup, but that's not "as simple as possible".

HTSC