Can any hard-drives be bought and configured to work in the caddies inside this unit?
Or do you have to use a specific kind manufactured by Alesis?
According to the manufacturers website:
This means that you can get a drive from anywhere, but it only accepts the older PATA drives. Currently New Egg still has a few at < $100USD.
Any brand of drive will do, but I would recommend either Seagate or Western Digital.