Everyone one of those characters is advanced in the fire element, but the gloves go to Madara. 1-he is an Uchiha, a clan known for being the best fire release users. 2-he is the strongest Uchiha, thus being able to use fire release to great lengths. You could also say that SO6P or his sons are the best fire release users, but kishi has not said anything about that so for now it is Madara.