Best 5/6 link for Scorching Ray?

I was thinking about:
Scorching Ray + Elemental Focus + Controlled Destruction + Rapid Decay + Increased Burning Damage + Empower

or perhaps I should replace some with Cast when Channeling + Flame Surge?
Or better give Flame Surge on Spell Totem?

note: I will be using Searing Touch Staff

Drop increase burning, it's garbage.

Either use faster casting for better movement andfaster stacking or increase duration to allow to stop channeling to avoid an attack without loosing your stacks.