Hey I'm currently a bit confused. If I'm aiming for Universities in the USA, should I go for A Levels, or should I apply for SAT? If I do apply for SAT, how do I study for it and take the exam?

To be honest, I am aiming high here, I'm hoping to get into Harvard University (good luck on that huh) but seriously, hope there's some solid advice as to what to take after SPM, hope to start planning Asap, because on their site it seems that they only require SAT tests as the foundation (even for international students) is this true? Why do you take the extra mile to take A levels when you could take SATs after SPM and just go?

Hoping for answers! ^.^ Thanks!!!