There should be a word to define something between a want and a need. Perhaps ask him what he needs on a purely emotional level to feel satisfied in a relationship? What he hopes to receive in this relationship? What he hopes the two of you can share?
I think the "I don't need anything and I just want to love you for being you" approach is sweet....but I also think it's a little bit of a cop out (if you'll excuse me on this). I'm sure he knew what you meant, or at least had some idea what you meant by the question. Explain to him what you're trying to do and what you have listed and then ask again. Communication is a two way street.