Kind of off topic, but stay well hydrated, local pharmacies have Diamox if necessary (check with physician or pharmacist before use, of course,) be aware the oft-proffered coca tea is harmless (no catalyst and infinitesimally small amounts of potential cocaine hydrochloride).

If you want a base, check the non-profit South American Explorers (they have clubouses in Lima and Cusco, as well as Buenos Aires and Quito) here. (Full disclosure - I am an avid lifetime member.)