You're going to find it very hard to get players that can play so versatile at left, right and centre.
Retrain your defenders on their best foot first so that it gives you more cover and, if you're feeling confident, re-train them onto their other foot - provided that they can retain the first re-training.
DMF's suggestions are the only ones that come to mind, as well as Petri Pasanen and another from the Bundesliga - I forgot his name.