you dont have the black ice build on your profile, so it's hard to gauge what skills you'll be using aside from black ice.
Try getting more items with chance to crit on ray of frost like mehttp://us.battle.net/d3/en/profile/HachiKumo-6695/hero/23342293
mara keidoscope is the most important piece and it should also be the most expensive part of your gear.
90+ crit dmg, crit chance, >200 int AND high % for RoF will be very expensive. Try to settle with some of the mentioned.
SoJ with RoF should be cheap, getting high elite bonus is good.
As for the mechanism, since RoF is a channeling skill, you should get your dps up in the following priorities, critical chance, critical dmg, intelligence, damage modifier, attack speed.
Attack speed does increase your damage output, but channeling consume resource at much faster rate.
The reason to get Critical chance first is to make use of Arcane Power on Crit(Apoc) in which you can continuously fire your ray. Power Hungry refill your arcane quickly too, so apoc isn't really compulsory. The idea is to kill fast so that black ices appears.
Last but not least, gear your gloves last, so unless you have a very awesome >trifecta gloves, you can consider frostburn gauntlet for a slightly better damage at a very much cheaper cost.
*My 2nd wizard is actually a mule, so I don't play with it often, she can still play quite well in mp4 though. I dumped all interesting yet useless items on her ><