You're also covering thousands of miles of dense forest, with very few options for emergency landings. Mountains, sea - I personally can't think of anything else that scares me as much as jungle - you go down there and they'll never find you. You could perhaps go up the coast, then cut west at Belem and track the Amazon past Manaus and that way (especially with an amphib), but you'll eventually have to make a choice of going over the Andes or go back up north to the coast. I'm not very familiar with the Andes, but it looks like you could cut across around north of Bogota at a reasonable altitude following the 62 highway.
A great adventure, indeed! I'd fly it, but make plenty of time for the inevitable bad weather and other stuff that you probably will encounter and always have an option.
Last edited by AdamFrisch; 1st May 2012 at 06:58.