for schafers you need 120% ias overall (aka 100% from gear)

for 0 base weapon speed (zerker mythical conquest mighty scepter falcata tyrant reinforced mace) you need 60% ias

aka bfist+highlord+20% ias glove+edias jewel in armor/shield/helm

or 2*edias's socketed among armor/shield/helm
(160/30/30, or edias valor+edias helm/shield, edias helm+shield etc etc)

as long as you have atleast 60% ias youre good.