With 2...it might make more of a difference, but leveling 5 shamans the only gear I got was from the quests I did - I just made sure to have a shield on each one and that made instancing fairly easy. I wouldn't worry about gear for regular questing at all as 2 shamans will be able to plow through stuff even with fairly crappy gear. Maybe try to focus on getting some int so you run out of mana less (shamans have huge mana issues until outland gear + water shield).