Two More Pokemon For My Team?

I have a Serperior (Grass), an Excadrill (Ground/Steel), a Carracosta (Water/Rock), and a Litwick (Fire/Ghost). I have five gym badges and want a complete team and have been looking into the next two pokemon I want. I was thinking some flying or levitating pokemon to help with my weakness to ground pokemon but I also need help fending off fighting type pokemon for the same purpose. Which two of these five pokemon should I add to my team, Hydreigon, Braviary, Haxorus, Eelektross or Galvantula? I like these five pokemon the best to help my team. Other pokemon can be suggested.