hi i got question about merc from act 3, exactly

i make cser hammerdin, and dont know which eq, i should use on him, need kb aura, i remember its from azurewrath,

which eq i should use on it?

azurewrath
phoenix mon
which armor and helm???

and best is buying merc act 3 cold on which difficulty?

sry for my english

thx for answers and help !