On isomorphism: every version of utilitarianism I know of leads to a repugnant conclusion of one way or another, or even multiple ones. I don't think that deontology and virtue ethics are nearly as susceptible. In other words, you cannot construct a utilitarian equivalent of an ethical system which is against suffering (without explicitly minimizing some negative utility) but does not value torture over dust specks.

EDIT: see the link in this lukeprog's comment. for limits of consequentialization.