Yeah, you're not going to get Chaos I think. If its any consolation, aside from being a gimmicky 'cool character' with a laughable backstory (and by saying this I'm not claiming certain other characters like Cait Sith have better ones), Vincent doesn't have much going for him. As powerful as Chaos can get, the sheer unpredictability and the fact that you can't tell him to heal one of your friends diminishes his usability.
Go train Cid and Barrett. That being said, I totally sympathize if you wanted to use him because you liked him. My favorite characters (Nanaki and Yuffie) got craptastic limit level 4s (although they have above average level 2/3 limits which i use late game)