What type of government does Jack claim the boys should have?

I don't think Jack was ever sophisticated enough to claim a specific type of government. From chapter one he wanted to be chief and dictator. Most of the novel has Jack challenging Ralph's authority and grooming the boys for his eventual assent ion to the throne. In Chapter 6, Jack does demand, "it's time some people knew the've got to keep quiet and leave deciding to the rest of us". The rest of us meaning himself. Jack wants to be the unchallenged dictator of the island.