I am getting the Beating the E4 With Ground types. Here is my selection of team:
Swampert Level 100 @ Leftovers
GABBY (Gabite) Level 50 @ Dragon Gem
You have to have access to the Pokemon Dream World to do this.
Gligar can be found in Windswept Sky with it's hidden ability, Immunity. Evolve it into Gliscor and it will have Poison Heal.
Hope this helps you.