Sounds like fun. I did it last year. Didn't even come close to S.A though. haha.
I suggest ditching the camp stove and all the crap that comes with that. You won't need it. Pack some granola bars for mornings and nights where food isn't available right away. Otherwise, food is everywhere in Mexico and most countries south.
Good luck! Remember to enjoy it, even when things aren't going well. Beats the hell out of the routine back home...