Synology NAS. Seagate Ironwolf hard drives are a good pairing. You can setup your NAS to backup to AWS Deep Glacier or GCP equivalent so you have redundancy still.

Synology is good out of the box. I have a custom-ish U-NAS case.

Note that RAID isn't a replacement for backups. Personally, I just use USB-connected drives, Time Machine backups (on a Mac), and Backblaze for a secondary cloud backup.