I'd say your best bet it choosing HP and one of the defenses to focus your investment in instead of splitting them. Carbink's HP stat is fairly poor, so it will be important to helping it stay alive longer. Which of those defenses will depend on what your team looks like and what you intend to tank with it.
For the attacking move, Moonblast is usually preferred as it can help in a support role with an added effect of a Sp. Attack drop.