Have you tried training in Vibram 5 Fingers yet? Did you know that barefoot training is podiatrist recommended? Especially if you have flat feet! I learned this after speaking personally with Dr. Emily Splichal. She has recommended that her flat footed clients run in the glove-like shoes in addition to doing balance training and hip stability exercises.
For more on what she has to say, read this article: Barefoot Training Revealed with Dr. Emily Splichal - New York NY