I own both these units and they need new hard drives. Can I use any 2TB drives? I was thinking about WD Purple drives. Someone mentioned that the HR24 drive needs to be 2.5” but I'm not sure. I was also thinking about going external but I think the eSATA docking stations are hard to find now. Does anyone know for sure? DirecTV wants to swap me out with a new whole-home system which I'm not interested in.