So is this a Combustion Blast Charizard deck that uses cards like Blacksmith and DCE to get Charizards, or is it something with a different Charizard?
For this post, I assuming it's speed Combustion Blast Charizard with Blacksmith and DCE.
I like Mega Houndoom because with Giovanni's, it can knock out EXs for just two energy or a Blacksmith(though you'll have to power it up on a different turn since you can only play one supporter a turn.)
For Camurupt, it takes too many energies, especially compared to Charizard who can do 170 with a Muscle Band and not have to discard any energies.