Baños is the densest adventure market in the country: ninety-six registered agencies in a town of twenty thousand, all selling canyoning, rafting, bridge jumps and the waterfall route, frequently to each other's customers. Almost nothing is priced publicly — you walk in, or you message, and you are quoted on the day.
The agencies below are the ones that publish a real website with contact details you can check. A great many more exist with nothing but a Facebook page, which is fine if you are already standing on Ambato street and less useful before you arrive.