So my daughter is level 50, and wants to respec to a dex mage. I've seen a lot of discussion on her about the dex mage. My questions are these...

Which is better... the 140/139 split, or the 173/rest INT split?? And why??

How should her skills be set up?? Right now she has 1 in mana, rev, and frostbite, 3 in ice storm, 4 in nightmare and horror, 5 in drainlife, and both blessing skills, 6 in everything else. Everything 4 and above she is planning on maxing out right now.

She already has the void gear.

Thanks in advance for the opinions!!