You would normally use either Ice types or Dragon types to attack, and Steel types to defend.
The two Pokemon you listed sound pretty good and will work great, but i'll recommend 2 more Pokes.
Another Steel type that would work well for defending is Ferrothorn who has really high defense and can sponge any Dragon type attack they throw at you. In return, you can hit it with a STAB Gyro Ball or another attack move, some type of status, or Leech Seed them which will really help you out in battle.
As for another offensive Pokemon, Vanniluxe is the only worthwhile Ice type at that stage IMO, so I will recommend the Haxorus line. They have good speed and can outrun Drayden's Dragons if you put in a few Speed EVs and they have godly attack and will do huge amounts of damage with its Dragon STAB.
Hope this helps! :)