First Wyvern: 15 U divine weapon, 15 R arcane item, 14 R heavy armor, 15 R arcane item, (18 R shield)
I did it this time with my two Wizard/Priest Firestorm farming team, with some extra armor discard. Two Warriors and a Wizard also work fairly well if you have some decent armor with Grounding Plates. Really any combination of Grounding Plates, Resistant Hide, and armor discard will be pretty effective.
Believe it or not, Dragonslayer Sword does a pretty good number on Wyverns. And AotA brought Sundering Strike on a bunch of gear. I usually punk this by running fighter-fighter-priest with a ton of MF, Martyr's, steps, and armor-shredding.
I used a Warrior, Priest, and Wizard using step attacks, wavering faith, and armor destruction. UURR(R)
Second wyvern: 17 U treasure, 17 R treasure, 15 R arcane item, 15 E weapon, (15 R arcane item) Gleaming Glaive, and my elfs are now level 18 build used: http://forums.cardhunter.com/threads/sp-wyvern-whackers.5925/