It'd be smarter to go for Earthquake. Ferrothorn isn't exactly OU in-game.
Then how about Nidoqueen?
I believe so, she naturally learns Earth power, superpower, crunch, toxic spikes, and a couple of moves which will help her. She also can learn quite a few TM's, but I don't know how the skill inheritance will affect her, unfortunately Would have suggested Nidoking but he doesn't learn any fighting moves.