I'm currently planning a trip to South America for August 2010 but I'm finding it hard to evaluate the safety, reliability and cost-efficiency of buses in west South America. After arriving in Quito (Ecuador), I'm looking at travelling down to Lima, then Cuzco and La Paz. I'm pretty confident that busing it from Lima to La paz will be fine with a few stopovers. But I'm concernd about the Quito-Lima route. Has anyone taken this route by bus before? What are the stopovers worth stopping at? Are the buses in this region reliable, or are the roads dangerous and is it probable the trip will take many more hours than predicted? If I have to take many stopovers because of the length of the trip and will hence be stopping at many other cities and towns along the way, would it still be much cheaper than simply catching a plane from Quito to Lima? How safe are the buses themselves in this region, considering I'm an 18 y/o female travelling with one male companion? I'm looking at taking as many stopovers as needed to keep the longest bus ride at about 15 hours.