Only a blithering idiot, or a neocon ( but i repeat myself) would support installing a king.
They have lived under despotism since 1953 of either the Shah and Savak, or the Ayatollahs.
Maybe they need a chance to have some normal freedom. As a people the persians are much more intelligent and better suited to this than arabs.
However, if the Ayatollahs fall, would the Iranian Guard quickly fill the power vacuum? In my opinion that would be more oppressive than the current theocracy.