I was down there around this time a few years ago and met up with a young guy named Pablo, but everybody calls him Pingullio. He safety boats for a number of different whitewater companies down there, one of which is Rios Ecuador. He is a great guy and has family in Mishualli, so he lined up shuttles and food for us, lots of connections. Not sure how to contact him now but hitting up Rios Ecuador might be a start. I do know he's in Banos quite a bit this time of year.
Also, the Welcome Break is a great place to stay, and the Tortuga Cafe is great for breakfast.