There's a lot of choices.
I chose Rapidash (of course).
Arcanine is also a good choice, since you can get Extremespeed. But he have a poor moveset.
Magcargo is perfect if you need both fire, rock and ground moves. But he's slow.
Flareon is not so good. He have low hp and defence stats, so he can get killed easily.
The Sunny Day, Solarbeam combo is very good since you can supereffective all the fire type weaknesses. (Water, Rock, Ground.)
Movesets:
My Rapidash:
~Sunny Day
~Solarbeam
~Flamethrower
~Body Slam
Arcanine:
-Extremespeed
-Flamethrower
-Maybe Solarbeam + Sunny Day
Magcargo:
-Flamethrower
-Rock Slide
-Earthquake
-Smog/ Yawn
Give your fire type a Charcoal, which will boost your fire type attack.
Good luck
Also... Calm Mind for your Kadabra?