First of all, Noivern is not even close to viable in Anything Goes. It's better in RU and Monotype. Heavy-Duty Boots are the best item for Noivern, because it's weak to Stealth Rock and acts as a pivoter with U-turn. It's prone to getting chipped down by the very prevalent hazards.
Choice Specs are probably the second best choice, as they really help Noivern rip a hole in a lot of things. STAB Specs Draco Meteor hits hard. Do note that if you plan on switching in and out, you'll be worn down a lot.
Hope I helped!