I was thinking the same but then in the IRC today someone mentioned the performance gain and resilver time being much more efficient with the smaller vdevs of z1. Also the fact that if I ever want to grow my pool by swapping out drives with larger ones, it will be cheaper doing 4 vs all 8 at a time. I would be able to lose two drives just not in the same vdev... but in the off chance that would happen I still have my backup server.
So I am confused and ended up with option 2. If its not still the recommended way it not too late. I can start over :)
These are all valid points but it really just depends on what you want. The reason people often don't recommend raidz1 anymore is because drive sizes have increase greatly since the days when a 1tb drive was not common. If you are using larger drives (which you are) and a drive dies, you will be fine. However, when the array starts to resilver, the chance of another disk getting an error during the resilver process is not rare, to the point where most people don't take the risk and rightfully so don't recommend others either. If another drive dies during the resilver process on a raidz1 vdev, you're data is toast, the whole pool.
Multiple people on here have backups and that is fine if you don't care about downtime and can handle the time and effort it takes to restore from a backup. Personally, while I have a whole second freenas box dedicated to being a replication target, I still use raidz2 because I don't want to have to deal with the hassle of having to restore my tbs and tbs of data when/if my pool goes down.
It's all a personal choice. If you understand the tradeoffs and understand how the raidz levels work in terms of function, behavior during failures, and so forth, then by all means go with whatever is appropriate and you feel fits your needs/comfort level.
