We are planning a similar trip, and we are also trying to figure out what to do. So far in my planning, much inspired by this thread, I have mapped out the following route for ourselfs:
Its very similar to what loubylou outlined, with the addition of some more overland travel, Piratia and the Amazon. we are still trying to figure out the details, but where planning on playing it mostly by ear.
Dont want to hijack the thread, but guess its the same thing, so if anyone has any comments, that would be much appreciated!