I've ordered the following parts for my first FreeNAS build...
CPU:
Intel i3-4130
PSU:
SeaSonic SSR-360GP
HDD: 6x
3TB Western Digital Red (configured in RAIDZ2)
RAM:
Kingston 16GB ValueRAM 1333 MHz ECC CL9
Case:
Fractal Design Node 304
Mobo:
ASRock E3C226D2I LGA 1150 Mini-ITX
So this ASRock mobo... there is also a C224 variant (supposedly) but I couldn't find it for sale anywhere. Even this variant is only at a couple of non-mainstream sites (
www.superbiiz.com is where I found it). Basically, it's the only mITX Haswell board with ECC that I could find, period. On paper, it's almost an exact clone of the Supermicro X10SLM+-F, just shrunk down. Only 2 RAM slots, but I won't need more than 16 GB of RAM for my system... since I'm filling up the case and board SATA slots (yes, there are actually 6 SATAIII ports on this board) I won't need any expansion card either.
So the obvious risk is that I haven't found a single case of this board being used for FreeNAS... but it does list FreeBSD 9.1 on the list of compatible OS's, and the Intel GigE chipsets have worked for other builds. So I'll be the guinea pig! But I figured there might be some interest out there with regard to a Haswell mITX board. It's a little pricier, but I decided it was worth it to have a smaller system instead of just another mid tower (let's be honest... uATX cases aren't really all that small).