Most of what you find is going to be fake "shamans" ripping off Americans to make a living. I personally wouldn't trust any recommendations shared here, nor on any other public forum besides those filled with genuinely seeking, self-healing, and spiritually minded individuals. Taking ayahuasca in SA isn't a walk in the park, nor a game, there is dark and shady shit going on down there these days due to the increased attention and tourism from NA and Europe.
This is not the place to either A) disseminate information on legitimate shamans and healers and B) find such information.