getting around in SA

[zmsmith5]

I am in the very early planning stages of a RTW, year(ish)-long trip, and one of the last legs of my trip will be South America. I was wondering how difficult or how long it takes to travel around in SA by train, bus, etc. Im planning to fly in from the Europe leg of my trip into Buenos Aires or Rio and then make my way through the continent to Peru for the Incan ruins and then go as the wind takes me until Ill finish off in the Caribbean somewhere before heading home. Im wondering if I could get around easily by train or whatever throughout the continent of if I would save time, money, and grief by just flying. Any advice would be welcome, thanks.