We will be staying in Quito and want to visit Cuenca and some cities or towns along the way. However, we won't have time to take the bus (or a hired car?) round-trip. Does anyone know about flights between Quito and Cuenca -- who flys that route and how easy it is to book? We thought we might fly down and then take a bus or car back. Any advice about things to do along the way would be appreciated.