You don't need one of each, I did it and all 3 of us were defender class titans with helm of st.14. With the right perks enough orbs were being generated that we almost had constant bubbles. Sunsinger warlocks are useful for a self res clutch but I would say bladedancer hunters and defender titans are more useful especially on the mines.
I posted this link up a few pages ago for a right hand camp for Skolas. It looks quite dooable and this was one guy pulling along two guys who had never done it before.
Skolas' Revenge - Right Side Camp