This build was on my to-do list for almost 3 years. I also thought about buying one of synology 4-bay NAS units recently but decided against it. This freeNAS build has more room for future upgrades. Also the main reason is i just wanted to build a PC, missed it for so long.
Thanks a lot to folks at techenclave for helping me to finalize the build.
Initially i had lot of problems with transmission (bit torrent client). Other than that freeNAS installation was very easy. You can check my bookmarks related to freeNAS. I have setup three 2 TB drives in RAIDZ configuration. freeNAS is installed on to a 8GB USB stick.