Little NAS boxes are pretty nice but how much storage are you thinking you want? That is going to guide your solution more than anything I think. I wanted more than a simple little NAS box could offer, my current hardware plan maxes out at 14 hard drives and that's a fairly normal home server machine from what I gather. I only have five drives now with just under 6TB in use and my movie collection really isn't that big IMO with a mix of DVD and bluray. I would prefer to build a real server and keep options open.
You could check out freenas too.
I choose home server because it was easy and supported my movies in that box, plus I got backups for the clients as a throw in feature. I am not locked into that though, I was also considering XP or something like freenas or a favorite linux distro. WHS just seemed to offer the most features and ease of setup.
Atom D510 Supermicro X7SPA-HF, Geil 2GB, 2x 750GB Seagate, 2x 2TB Seagate, 1TB Samsung F1, Win Home Server. That motherboard has IPMI 2 with KVM and media over IP, making the box truly headless. I installed the OS without laying a hand on the box.
I have plans to add a supermicro SASLP-MV8 to get 8 more drives in the computer which will fill the case.http://www.hardforum.com/showthread.php?t=1397855
Beyond that you might want to consider a port expander.http://www.hardforum.com/showthread.php?t=1484614
My case is this:http://www.virtual-hideout.net/revie...se/index.shtmlhttp://www.yycase.com/yy-0221.htm
But there are better options now:http://www.newegg.com/Product/Produc...-031-_-Product
I am not mentioning high end hardware RAID cards here because you don't need it on a low end home media box but I do strongly recommend that you either do folder duplication (home server) on anything you don't want to lose or software RAID 5 (linux/freenas etc).