Prestashop 1.6.1.5 Make City Select

This is a new installation of Prestashop 1.6.1.5 and need the City to be a dropdown choice for the client instead of a field to complete. The city choice should be created the same way as the states within the country (meaning as each country has its' states, so each state should have its' cities to choose from). This should be implemented in front office and also in backoffice, allowing modification of the city database later on. The front office changes should be implemented in: shoping cart, authentication page, new address page, modify address page, etc. The backoffice modification should include the cities list similar to the states list already implemented and also changes to the new address page, modify address page (also from the order), create new order. This is important because we are currently not able to restrict people from different other cities where we cant serve. Thank you