So, have you decided yet?
Yes, I know, I'm digging up an old thread, but this is one of my favourite topics, so I might actually be able to help.
First of all, I think budget and time are two of the most important issues. If he wants to build his own box but hasn't got the time, he'll probably be better off going off-the-shelf; and budget boundaries might tell us how many disks he might have be able to have. single and dual-disk NASes are rather cheap...
That being said, the Mediasmart series from HP seems to be a great starting point. From one to four disks (BYOD for at least the third and fourth ones on some models, and there is actually a single-disk, non-upgradeable entry-level model, too), WHS (which I use and absolutely recommend, the backup, duplication and Drive Extender capabilities are just great), and a nifty little package with quite a punch in the "SOHO-oriented" models (the only real differences are the dual core 2.5GHz CPU and the model name, plus hot-plug on the eSATA port, if I recall it correctly).
For about the same price as a Mediasmart, but much bigger, you can build a new WHS box, with up to 15 HDD bays (though hot-swap will not be available), and even more, but when you get that big price will rear its ugly head with full force.
Hope this helps.
Cheers.
Miguel
Time will tell.
