Puppy Classes - What next?

Next Sunday Jack is graduating from Puppy Class. His obedience is great - his socializing is improving but still has a long way to go. We have a bunch of tools and plans to help him work on it which is great. I know that each small improvement is better than nothing. My next decision is whether I want to do more 1 on 1 classes or a group puppy class. I'm not sure. His issue is NOT the obedience. His back of tricks includes sit, stay, down, come, roll over, roll on his back, shake a paw and sit pretty. The dog will learn anything I want to teach him - he is just way too shy outside of the house. So, will doing basic obedience puppy class in a group be the right choice? Or, should I do one on one classes again where we can change locations, choose dogs to meet with, etc? I'm not sure yet. The trainer said what ever I think... maybe I can do both. Who knows.