Discuss Which form of government would you advise Riverland to adopt?

Topic: Which form of government would you advise Riverland to adopt? Please answer by reference to relevant material on Forms of Government and real-world examples.

Paper details:

After gaining independence as a result of de-colonization, the state of Riverland adopted a presidential Form of Government. Soon after, an authoritarian leader was voted into power and governed the country for over 20 years by concentrating powers in his hands. Revolution ensued, as a result of which Riverland is currently drafting a new constitution. You are hired as a consultant by the government of Riverland.

Please list the sources used at the end of the essay, thank you
In case of doubt, refer to Mark Tushnet, “Advanced Introduction to Comparative Constitutional law”