Wow, I appreciate the outpour of recommendations. I'll definitely sift through these in my planning portion.
I plan to do quite a bit of cheap bus travel and tent camping as much as possible. Mainly I beg the question, is two months too short (or rushed) to make it down from Bogota to Buenos Aires and back again? It's much cheaper to fly from North America to Bogota than any South American city and one-way tickets are wayyyyyy too expensive!