Hello,
If you disconnect power, HD's components will receive data (0/5V) without be powered, it's not safe.
why dont you use a rack ?
It's the better solution IMHO.
PowerMac 3.5, G4 1.0GHz DP, 1GB ram, 80GB HD + NAS, Radeon 9600 128MB Mac, 1680x1050
PowerMac 7.3, G5 2.3GHz DP, 4GB ram, 160GB HD + NAS, Radeon 9800 128MB PC, 1680x1050
Amiga 500+, Vampire 500v2+, HxC Floppy