jtwj

It isn't listed as compatible because it isn't officially supported.
Wrt the build if you are going for a xeon then go for a WS variant of z87 boards and ECC memory. Most people go for xeons for the ECC memory support.
 
http://www.asus.com/Motherboards/Z87WS/#specifications

Unless you need the low power states of haswell, you could go for an i3 ivy and probably save some money. WD Reds seem like the go-to drives but I think Seagate drives are great too. I never had any problems with them. I would honestly just get the cheapest 7200 drives you can find and just test them thoroughly before deploying them. I would also suggest 2x8gb of ram. Maxing out the ram does wonders for FreeNAS systems.
 
As for RAID take a look at this tread by looney. Think this would be an ideal solution.
 
http://linustechtips.com/main/topic/33510-how-to-install-and-setup-flexraid-on-your-windows-storage-system/#entry429010
 
Hope this helps.
@looney

I personally would go for a 770 over a 760 if you are upgrading from a 660ti. As Ghost said performance per dollar it makes more sense to spend on a GPU upgrade rather than wc your current card. Most of the time wc is for aesthetics, reducing heat output or noise. 

Try plex. It will run as a background service on your gaming rig which can stream to your devices. It supports android ios windows phone and ps3.