I don't advise cooking turkey with stuffing in it, no matter how it's cooked. To get the internal cavity up to the proper temperature to kill the bacteria, you basically have to overcook the rest of the bird. The dark meat can take it, but this is what tends to dry out the breasts really badly.
Better to cook the turkey, save some of the cooking juices, and introduce those into the dressing (and gravy, obviously).
I don't know much about apples, but I hear Granny Smith are some of the best for cooking, because they don't end up too sweet. They're almost bitter when you eat them fresh, but lots of folks cook with them.