Well, they look healthy. If your going to re-pot them, I would do it a week or two before you begin to flower, in case of any transplant stress. Other than that, getting some more powerful lights to flower with would be a good idea; like a 250-400w HPS. You can wait as long as you like before you start to flower them, but they are ready if you choose now. However, keep in mind that they will stretch several inches before they produce buds after being put on 12/12.