For nightmare act II where we are I found this build to work like a charm - I also have topazes in all my sockets and the ruby in my wand. I finally found a wand and offhand that works well together. And I also wish we could have an armoury like they did in wow.
http://eu.battle.net/d3/en/calculato...XSj!bcX!ZbaaZa
That is my current build, altho at a later stage I will swop blizzard for something else, for now, it gives the group a nice slowing effect on groups of mobs.