NASLite Network Attached Storage

Howdy, I know this may be a simple question. I'm looking at putting up some NAS to serve 3 desktops in a Home Network (100 ethernet). I was looking at purchase a NAS appliance with it's associated costs when I stumbled across NASLite. Seems like a great idea.

I have a DELL PIII 933 Mhz PC with 256mb of Ram. It currently has a 20GB Hard Drive in it.

What I would like to do is install 2 500 GB drives in this box and either install a HW RAID controller or use the MIRROR function in NASLite and just Mirror it from one to the other every night. That may be easier.
Does that sound like a good plan?

Now once a month or every six months it would be nice to backup the NAS box for offsite storage. You can get those 500GB External USB drives for fairly cheap and it would be nice if you could just plug in the external USB drive and hit the button. But I know this is actually an operating system function.

To have NASLite see the external device is it plug and play? Or would you have to shut down NASLite, plug in the external USB, bring NASLite up and then once All 3 drives are seen just MIRROR the primary HDD to the External and then unplug it? Also, what format will the external hdd be in??? Or how if needed will I get a file off of the external HDD?

Last question, anyone have any current links to a small PC that would hold 2 HDD (either SATA or PATA) that has a USB port that would be good for this application and be low cost?

Boot with the USB external attached to the NASLite-2 computer. At that point it will be treated as any other drive, so you can mirror to it. Keep in mind that to disconnect the USB external drive you have to power down.

My brother in law suggest, just plug the External HDD into a USB port on one of the desktop computers and back up the NASLite share accross the network. Sure it is not going to be the fastest, but hopefully it will be done overnight...
That should work shouldn't it???

Any recomendations for a HARDWARE PCI RAID Controller???

Thanks folks!!!