Well I have had nas/file servers for many years now and I have finally found the perfect combination of redunancy and storage capacity. At this point most would say this is probally overkill , but hey go big or go home right.
Main storage server is my freenas box with is
Core I7 4770k
16gig usb stick for OS
4tb x 6 zfs2 all western digital Reds (media )
4tb x 6 zfs2 all Western Digital Reds (games,photos,backups,misc)
zfs2= I can have up to two hard drives fail and resilver without losing any data. If i loose third one then I loose entire pool
My secondary Server is a dual purpose system.. It is built around windows 10 . I currently use as my HTPC, backup raid, and secondary plex server. I am using whats called Flexraid which is software over windows. This is nice software cause you can have as many hard drives as you want in the pool. There is a few rules such as biggest drive has to be the parity drive and there is a cost in licensing. Please see http://www.flexraid.com/ for more information regarding this product.
This system specs
250gig ssd for os and plex caching of meta data
I have a mix of 4tb and 5tb drives in this pool. Please see photos for setup