[NAS] [atv2] [ios] NAS recommendation for two simultaneous atv2 streams

So my WHS is on the verge of dying, and since MS decided to kill drive extender i won't be going to Vail...

So I'm close to getting a Synology or QNAP, but with so many options out there I was wanting some owner experiences using NAS hardware (two or four drives) to stream to multiple atv2 boxes at the same time. Right now, one atv2 is wired, the other is wireless, with a third on the way (also wireless - running all cat5 is not possible at my home).

e.g.
-since there are so many options out there (processor, ram, etc) are there any minimum specs to look for?
-if you ever stream at the same time, can you please provide an opinion on your setup and what's working well or would have liked to know beforehand
-most of the other threads have pretty low requirements (e.g. the synology 211j seems to be a favorite) - but I'm wondering if, for my needs, i'd need something like a 211 or 211+

Not sure if this matters, but, I barely have any 1080p files, most are either 720p or below, and a mix of native and non-native formats (avi xvid).

Thanks in advance for any advice

Any option will be fine. A NAS should support 20 users or more at once. My point is don't stress it.

Unraid - http://lime-technology.com

As I said in another thread I would not buy "J" versions. They have file transfer speeds as my wifi connection. YMMV, though.