I would like to get from Popayán, Colombia to Quito, Ecuador by bus. It would be very nice to get comfortable overnight bus. Is it possible? Where I can get such information?
It does not appear that there are any direct buses, though it probably wouldn't hurt to pop in to the bus terminal in Popayán and ask. Failing that, the most straightforward route is to take a bus (7–8 hours) from Popayán to the border town of Ipiales, from which you can take a minibus or taxi to Tulcán, Ecuador, and from there a bus (about 4 hours) to Quito.