Upvote:0
This definitely works: Uyuni to Calama, Calama to San Pedro de Atacama, San Pedro to Salta, Salta to Iguazu.
This probably works: Uyuni to Sucre or Potosi, Sucre or Potosi to Asuncion, Asuncion to Iguazu.
It won't be to easy to get timetables online for Bolivia or Paraguay. You will just have to go. :)
Upvote:2
Have you looked at the map? That's a long ways away. I don't know exactly but it's going to take a few days to get from Uyuni to Iguazu. What's going to take you longest is having to stop at destinations while waiting for the next busy. I recommend not trying to go straight through and instead make a few stops and enjoy the local places where very few people go. The main issue is that you're going to have is that Bolivia and Paraguay don't have a very organized bus system. They are not at all comfortable although it's going to be very cheap.