Perhaps, we were staying close by at the Metro Marlowe too, but they were not open at 6am. I suppose I could have purchased one the previous night but then it would have been cold by the morning.Too bad they don't sell them on the train.
Had a meat pie for breakfast this morning, it was on the train Sydney to Canberra. Not great and I couldn't tell what the brand was. They have switched brands in the last few months and it was certainly not as good as the one I had back in January.
Australians do not currently need a Visa for Argentina or Uruguay however we did have to fill in an entry form for Argentina.
Brazil and Chile you definitely will need a visa so use the official links via smartraveller and apply within the appropriate times to allow processing.
As for Peru and Ecuador, I cannot remember what the requirements were as we were there 10 years ago but smartraveller will have the info.