Rune: 20%ES or 2% Max Mana?

I'm doing Archmage+CI+Eldritch Battery+MoM, around 5600 ES, 4200 Mana. Which 1209 ES from my gear turns into Mana.
I need help deciding/visualizing which rune would be better to use on my gear to maxout Mana/ES as much as possible.

Either 20% ES or 2% Max Mana.

ES Values
Helmet: 244
Body: 624
Boots: 180
Focus: 94
Gloves: 67