We had a local spot that did the cracked eggs on top of a bacon and sausage pizza. It was awesome, but they got rid of their pizza oven and replaced it with a smoker. (They make some decent Q now, too!)
The trick is to set the white while leaving the yolk runny. So wait until the last couple of minutes cooking the pizza to add the eggs. That way the heat from the pizza toppings underneath help sets the egg. If you wait and add the eggs after the pizza is done and off the KK, there's not enough heat left to set the eggs properly (whites stay runny). If you add the eggs at the beginning, they'll overcook (IMHO). Last secret, crack the eggs individually into a bowl, then gently pour onto the pizza one at a time. Given the rough surface of the toppings, if you try and crack the eggs directly out of the shell onto the pizza, the yolks will usually break.