Now you are talking. Other than the name, the Amazon is often a great disappointment as far as wildlife is concerned. It's all there, but the thick jungle doesn't allow much observation.
On the other hand, the Pantanal is more open and you would be unlucky not to have great wildlife viewing. Here's a good overview of the Pantanal:
http://www.pantanal.org/pantanal.htmIt is important to consider that the Pantanal has two seasons: a wet season from roughly October to March, and a dry season from April to September. About 80 percent of the rain falls during the wet season. The wet season is the best time to view wildlife as it is highly concentrated on the few dry spots left in the wetlands.
Although distances are immense in Brazil, it will be possible to travel from the Pantanal to Foz do Iguaçu, and then on to Rio very economically by bus.
Keep in touch to let us know how things are proceeding.