Between the British Airways Visa ($2000) and Chase Sapphire ($4000) the OP will eat up most of his $8000 tuition payment. Also consider getting the Chase Freedom card. It has a low sign up bonus, but the "points" transfers to the same pool as the Chase Sapphire, which can then be transferred to BA for use on AA or LAN.

For the rest of your spending, I suggest looking at hotel cards? However, I'm not sure what hotels chains are common in South America, or if you are planning to slum it (hostels, guest houses), or ball it (5* hotels, resorts).

You need to apply for 2 credit cards with the highest spending requirement now, as it normally take 2 weeks to get the card, and you need to get the card before your tuition fee is due...