Dreamscarred Press - Tzocatl, The First Language: Open Playtest

[Ssalarn]

Another option would be using English words for South American ideas. My cultural savvy is a little weak in this area, but if you used naming conventions that convey the feeling you're looking for (more Jaguar Warrior, less Knight-Scholar) than you can keep the theme while cutting out the difficult to pronounce words.

Something like:

Instead of Advocate, Sunspeaker (again, cultural savvy low, so this just an example of what I'm getting at).

and language like "First Speech, or Tzocatl in the tongue of its earliest practitioners, is...."

That would let you simultaneously strengthen the theme, and increase the accessibility.