Thank you all for your input...I'm a little nervous about switching over and want everything to go as smooth as possible. FreeNAS has worked well for me but my setup is inefficient as I am mirroring all my data every night as a safety net. If I understand correctly with unRAID I can throw in a parity drive and double my available space by getting rid of my mirror.
Will this hardware be effective enough to feed 1080p to two XBMC settups?