hola c.jibia!
from this sideshore...
all southamerican countries, as far as i know they have got their own licences, if you want to work in there you need to convert your JAA licence (which is kind of a paperwork nightmare, and at the end, impossible..)
on top of that youŽll be required to be national in some countries (brazil, Venezuela...etc).
there are so many pilots working there already in this forum, i guess theyŽll have this info from experience..