This is a good moveset:
Swords Dance: Doubles attack stat.
X-Scissor: STAB, good power, high accuracy.
Earthquake: High power, high accuracy, double damage against Pokemon using Dig, used top deal with Poison (although not a weakness, they are annoying, Earthquake can also help against Weezing with Mold Breaker), Steel (which your moves aren't very effective against), and Fire types.
Stone Edge: High power, good chance for a critical hit, used to deal with Flying types and Fire types if Earthquake runs out of PP.