Well first for Ferrthorn you'll be better with a Physical set for him. Something like this:
@Iron Ball and ability Iron Barbs
This guy is a beast with curse. Ingrain is for healing. Power Whip is for STAB and is powerful. Gyro Ball+Some Curses=OHKO:) With guy is a wall with curse and will Sweep many Poke's with this trick and with the Iron Ball slowing you down thus making Gyro Ball Stronger, you have nothing to chance.
I think a Special set will work wonders with this guy:
@Absorb Bulb and ability Flash Fire
Metal Sound or Dragon Pulse
The reason why I put Metal Sound is so that you can lower the Opponents Sp. Defense in case you're having trouble dealing damage. Earth power is also for that and can kill Steel and Rock types who can hold Earthquake. Flash Cannon is for STAB and again can lower Opponents Sp. Defense. Absorb Bulb is for Sp. Attack raise incase of water attacks.
I think you should a Special Sweeper:D
@Leftovers and ability Serene Grace
Everything here is based on hax. Charge Beam all ready has a great chance for raising Sp. Attack but with Serene Grace it will always raise Sp. Attack:) Water Pulse is for coverage againist fire and confusion. Psychic cover fighting for the rest of the team.
This. Guy. Is. Awesome.
@Flying Gem and Ability Technican
I think this set is pretty self-exclamatory. Bug Bite and Bullet Punch get raised by Technican. The amazing Acrobatics tricks is awesome for killing. I don't need to explain Swords Dance. (Thanks to Scizornican for this set)
This guy is fire kiiler which is a must
@Life Orb and ability Torrent
Surf is for STAB. Ice Beam is a must. Flash Cannon is for STAB and a chance for Sp. defence. Aqua Ring is for healing
This guy is a beast period.
@Life Orb and ability Download
Bug Buzz is for STAB. The famous Bolt, Beam, Thower is a must
There you go.
(I got kind of lazy on the last few)