I don't see how you only have to build tank if you go jungle. I am not saying DON'T build tank, but if you need more DPS or AP, then go for that. Cho is pretty versatile, and you can really build him with just about any item from a pretty long list and he does just fine. I would say some sort of tanky cdr build would probably be the best though. He doesn't really get the farm to build stuff like Deathcap and Rylai's.