With 140TB+ of existing data, I would need 16 18TB HDDs to have RAID 1, and I also need the ability to expand. Really, I just need to have all the data accessible over the network so I can manage it from my main PC and stream it via a Plex/Jellyfin server. Maybe 4 smaller DIY NAS systems accessed by a separate system? I would really prefer no proprietary software if I can avoid it, and enterprise is out of my price range after I'll be spending $3,000+ on HDDs.