Runemaster has the better passives and combined with 5 points into Sorcerer for Static Orb and the aforementioned Mage Passive to convert Volcanic Orb and Static Orb to Cold would let you pair with Frost Wall and Runic Invocation for a Blizzard style AoE. You could have two orbs, a wall and a blizzard with the 5th slot for Flame Ward (also cold conversion)
Be aware that the build Scipo0419 described doesn’t play anything like a D2 Frozen Orb build. You cast everything but the Frozen Orb, and your damage comes from stacking DoTs on the enemy. The blizzard in question is a DoT too.
This is the gameplay of that build:
D2 Frozen Orb oriented gameplay style means:
casting the Frozen Orb yourself
not a DoT build
Sorcerer is the clear choice for that kind of build.