If you are willing to void your warranty, then it can can be pretty much any 2.5" laptop drive you can get your hands on.

A friend of mine told me that there may be incompatibilities between laptop drives from different manufacturers. He mentioned "grounding problems" but nothing more specific than that. Has anybody had any issues with a laptop drive not working with the empeg (apart from dimensions) or know what the exact problem might be?

Borislav