Disclaimer: full fluency, no studying required, but knowledge of the written language is not included.
Learning spoken Chinese without learning written Chinese is basically like only knowing half a language. Whereas learning spoken Italian and being familiar with the Roman alphabet would basically mean you could read it too, at least at a basic level. So much as I think it would be useful good to magically learn Chinese (which I am incidentally currently working on), the constraint of only being able to speak it tilts me in favour of Italian.