[John Rogers]

It seems to me for a home desktop PC you are trying to make things more complicated than necessary? I did not see what OS you are running, but maybe I missed it somewhere. If it were me I would drop the RAID idea completely and get several 2TB and one 8TB hard drives and have one be a solid state for the OS, maybe Windows? I would use the extra drives with one for business/teaching stuff if necessary, one for just images and one general purpose for downloads, ebook conversions, ETC. The 8TB drive is for backups twice a week minimum of all the other drives. I would make the Windows (or whatever you have) recovery drive(s) on at least 2 large thumb drives. IDE and SSD drives are super cheap at the small computer businesses run here in the San Diego area by Vietnamese or Japanese Chinese families.

While you're at I would buy a new large size case with several cooling fans and the largest power supply possible so it will not have to strain and that can cause device burn out if the voltage drops too low for the internal circuits!

Opps, I read your post again where you mention Windows, sorry.