Try these guys
Aeroclube de Santa Catarina - Escola de Aviação Civil for more information, I'm sure they will be very helpful. Most aeroclubes have a range of aircraft available, usually up to light twins.
They can also tell you about converting your licence, if you only intend to fly GA it's usually nothing more than a check ride and possibly taking the written tests, but it isn't a difficult process from what I've heard. Of course, if you have to take the written tests they are in Portuguese, however depending on your immigration status you might not need to convert anything.
As for speaking English, all major airports should have English available but smaller airports almost certainly will not, at least in Brazil.
TTFN