I am still debating, so far bug/ice, ice/fire, normal/ice, or normal/fire, fire/poison too. I usually try to cover electric type and earthquake since those are usually the most common and the most frustrating type I have to battle against to. That's why I usually have a ground and a pokemon that can avoid ground type moves.
If you look at my teams, usually there will be a/pair supporter, if I have one supporter I put a wall, 2 Sweepers Ph and 2 Sweeper Sp.
There always be or try to be a pokemon that can absorb water, electricity or ground in my team, that actually wasn't plan to counter you. It was me trying to build my team around that base. Right now, I am trying to see bug/ice since most of the one I want are already taken except fire and poison but because of the lack against ground type I try to chose another one.
that's why I usually run Sableye or Whimscott since they are the best supporter imo. I just recently found out another one. I am still testing them.