1) One stores 20gb and the other stores 120gb =) 2) IIRC, not with teh 360, but only with the older one 3) Yes, there is an ethernet port in the back. 4) I think they have wireless adapters for it, but you'll have to buy that. 5) That's extra, but if you put it on its side on a shoebox or something, it's not really needed.