"Pinnacle" btw iCANT
For the ES thing:
Im using Weapon swap specialization points.
Im speccing into Energy recharge rate on the skill tree for off-weapon which is a Wand+Focus, I have +3 to level of all spells skills on wand and +1 to level of all spells skills on focus shield to increase the ES recharge rate and using Meditate (from invoker ascendancy) to overflow ES.
Meditate recharge scales from spell skill levels and ES recharge rate from the items mods and tree.
The build itself is very straight forward and you can follow any "ice monk" guide and it will be basically the same.