Rapidash is probably the best option. As long as you give it Agility and Fire Spin, you're set. Fire Spin doesn't let enemies attack, and if you move first all the time, they're not going to be doing anything until you miss.
Edit- Flareon's base Special is higher than Charizard's by one point, Ninetales's by 10, and Arcanine is more physical and Magmar is plain bad, making Flareon your best option. It also can use the same set as mentioned above, so you should use it.