There are ways to reduced the areola if it is too large. Because of your age, however, I would recommend waiting until you are sure that breast growth is complete.
Because of the elastic component of subcutaneous tissues, patients with Ehlers-Danlos syndrome are more likely to develop sagging and irregularities in their breasts following breast augmentation than the average patient. Strategies for improvement would include use of textured, "gummy...
From your photo and description, I believe you are in the right ball park (240-260 cc implant). However, I would not agonize over the decision between the two sizes. Remember you are looking at a difference of only 20 cc. Taking into account that your natural breasts are...