doesn't matter as long as it fits in the network adapter properly and has no problems (so, in other words as long as it's compatible brand doesn't matter)
the hard drive has to fit the sony network adaptor. that beign said, not all hard drives will work. for example, no serial hd work (obviously) but also western digital drives have been tested and have a tough time fitting the adaptor and may even damage the adaptor if forced on. maxtor drives have had the most success.
