Working on a Fire Ball Build ( edited )

So I having been looking to plan out a fireball build for a while. I am looking for a few passive tree suggestions.


I will be using:


I also have 2 perfect rolled Rolling flame gems.


I intend to combine the damage boost from gang's Momentum with celestial punishment for a 40% combine damage boost vs ignited enemies.

Aside from that any good suggestions for what might be the best choice defensively? I am not the biggest fan of energy shield, but was considering armor/energy shield items.

The gem's in the gang's momentum are from another build that won't be in the Fb build.