you will already have infinity + cold mastery so you dont need cold mastery past -100% making doom pointless as a caster weapon.
if you are es you can try to use mp enigma for strength. i would use a nightwing and 5/5 cold for the ammi 2/20/mana.
frozen orb lacks the damage that blizzard has. es is a pvp skill and fails badly pvm. even with blizzard + es its easy to sorb.
why not try and test the gear in single player and see the difference using hero editor.