Science is not a requirement for the course, just to have passed grade 12 (or some form of tertiary education or PPL). My course was under the new recruitment process, and we have a mix of people from all sorts of different backgrounds. Pretty sure it's more whether you're the kind of person they want than what you did at school, which is what the testing is designed to discover. So I'd say apply now, you'll have the same chance either way, although having your PPL will make some things a little easier once you do get in
