My guesstimate is you have around 1,400 4K DVD rips. Do you need all of them?
You probably should look at RAID 6 with a cold spare (i.e. a drive sitting alongside the server.
ZFS allows you to create spare disks. ZFS spare disks are hot spares which are swapped in for faulty disks and swapped out when you replace the faulty disk.
I suggest that you calculate the cost to build this server, you should allow for NAS specific drives rather than the cheapest desktop drives.
You will need PCI to SATA cards to connect you drives.
I suggest that you look at the NAS builds on PC Part Picker.