Welcome to the Nexus

I totally understand the desire to participate in an indigenous ayahuasca session and travelling in south america. I suggest you really think it well though because depending how its done, I think might have negative consequences to the local culture. Check this post I made with some of my thoughts, maybe it helps you thinking about it.

Im glad you are not in the "yo lets get fucked up" attitude because that is exactly what we dont want here  Its good to use these experiences for personal growth, with respect and care.

Regarding suppliers, im not sure if you noticed but we have a whole subforum dedicated to it, so hopefully there you can find what you want:

Good luck!