Thats a very nice team you have there. I really like hail, so probs for using it.
Ive noticed one major weakness in Heatran, which you actually cant beat realibly.
If it has Toxic, which a lot of Heatrans carry these days your only safe switch-in is Tentacruel, but with Hail up, it wont live that long, especially when it gets burned by Lava Plume. To fix that, I would suggest using Starmie over Tentacruel or Earthquake on Aboma to effectly lure in Heatran.