Kinda depends on the rest of your team as well, but the basic idea is Gliscor for Toxic stall, Skarmory for hazards set up.
Skarmory's also harder to get rid of, with sturdy and no x4 weaknesses. Gliscor's x4 Ice weakness means a non-STAB Ice Beam or HP Ice will OHKO it.
I would personally go for Skarmory if you don't have Forretress or Ferrothorn already, and instead have Sheer Force Landorus instead of Gliscor.