Instead... just get something that will run OpenWRT. Check out this list: http://wiki.openwrt.org/toh/start. Running and configuring it at the command line is way more pleasant than you'd expect, and the (optional) web GUI is functional if inconsistent.
I've been using OMV for over a year now and it works great. ZFS would be nice, but having vanilla Debian, and the "world" of Linux software, is better for me personally. I was running a RAID 6 originally with OMV (software raid, no hardware raid card) with an external enclosure. I really didn't need that much space, so downgraded my hardware to just mirrored 3TB data drives and a 80GB 2.5" system drive in a really low-powered machine.
Thanks Volker for OMV!
That's basically a no-go for me by itself.
All depends on your needs.
Anyone using this method?