I was just wondering what you guys think about these two plants,
because they are easy as hell to grow indoors with no extra light
or anything. I live in a pretty cold area. Anyway I just wanted to know
which of the two is a more viable option for spice extraction.

where did you hear Big Medicine is easy to grow indoors with low light?

It's not.

I have 7 plants and I have never given them any extra light, given that since I moved them indoors for the winter I messed up and didn't hit them with my humidifier the dryness of the heat being on all day messed them up a little but they are still growing and hanging in there. Also I just started growing less than a year ago, my gardening skills were nil. That being said here they are and still foraging ahead. I'm sure jamie that providing them with all the perks they love they will grow even better. I'm just stating my experience with the plants I have.

Psychotria nexus is probably going to be a cleaner/easier extract.

Edit: The phalaris is a good source too, but I think you'll get a mixture of alks. Some goop. I've heard of people extracting from psychotria viridis though before and getting crystals.

Nexus has a better alkaloid content, and a better alkaloid profile. It grows much slower than the grass however. The grass is low yielding and has a wider alkaloid profile. Each has it's benefits and drawbacks, why not just grow both?

Yeah I do have both
I just wanted to know which one I should concentrate on
growing more of, just because I have a limited amount of space.
Thanks for the responses