The new WD Red drives that just came out are 8TB. If you require 8TB mirrored, you must have a gigantic collection! I've had good success with 3TB mirrored WD Red drives.

But I've also already migrated to Roon.

If you have an interest in eventually migrating to Roon, I would suggest going down the NAS route.

The MD600 is designed to be put in a different room, on the LAN, to not interfere with listening. Mine is in a rack in my garage. Ingenious rack/table-top design.

Primary: 818v3+ID41, M6 stereo pair, M SpeakerLink cabling, Sonos+96kHz Cullen, silver DSW
HT: Marantz prepro, 271, DSP3300, 8K SE FL/FR pair, DSP M6x2, DSP320x4 (ceiling), black DSW, 520 RL/RR rear in-walls
Living Room: G65, 640 L/R in-walls, UHD722, MS600
Vac. Home: G61, HD621, 4xDSP3100, DSP3100HC
MDMS:NUC/ROCK+TrueNAS Core 12.0 ZFS file server