With THAT little addition, I would say no to the Sony. It's more of a "casual reading" device than a tool. It has no search abilities, no real indexing, no marginalia and the page size would make textbook pages problematic.

I would say an Iliad at the least and would actually recommend more of a low-end tablet PC (form factor, handwriting recognition, multipurpose) or notebook PC (low cost, multipurpose) for educational purposes.