I messed around in GT today while I did some work to make a build for you. It’s something you could work towards and utilizes the suggestions that were made earlier by various posters in the thread today.
There is a focus on Health Regeneration and Cooldown Reduction while retaining the Dual Damage build original idea. If you can get the Trozan’s Skybreach set you’re well on your way to making something like this work. Eternity for a relic further reduces downtime on your sustain (Giant’s Blood/Mirror/etc) while increasing the frequency you can drop TSS and Storm Totems to get your damage going.
The only downside is the 165% Casting Speed, but that’s not that big of a deal since this build is primarily a cooldown caster.
Good luck and have fun with your build! 