Forretress gets Spikes, Stealth Rock, and Sticky Web. You could use a Focus Sash to ensure it gets at least one of those off. As it has just one weakness, it has fairly solid survivability.
Ferrothorn gets Spikes, Stealth Rock, and Leech Seed, plus a powerful Gyro Ball so you aren't Taunt bait. It generally lasts a while, but keep it away from Fire types.
Shuckle gets Stealth Rock and Infestation, which is quite annoying for an opponent. If you use Shell Smash + Contrary, Shuckle can last an absurdly long time, and it would be quite tricky to take it out.
Toxapex only gets Toxic Spikes, but it has incredible defenses and reliable recovery. As a hazard setter, it's probably the worst of the four, but it's still very good for other purposes (i.e. poisoning and stalling).
Overall, I would say any of the four work well. I would go for Shuckle, but you can use any of them.
Hope I helped!