None of the forum regulars use the 32 bit version and I know it doesn't get tested like the 64bit version. Don't bother with 32 bit - it will be a waste of time.
I have a 2x2Tb ZFS mirror, and even with such a small pool, my system is allocating 6.5 Gb of memory for various purposes. Take the 8Gb memory minimum seriously. Also, I suspect your setup does not support ECC memory, so you won't get much sympathy around here when you lose your data.
At the end of the day, you are not even close to the FreeNAS 9 recommended minimum's.