Do note that ASEAN Scholarships for Pre-U (Singapore-Cambridge A-Level) will be posting you to JC next year at the age of 19.
My cousin got through ASEAN Scholarship for Secondary 3, that was like in 2010.
Completed his A-levels in 2012 under ASEAN scholarship.

I'd personally applied after SPM 2014, and failed to get.

I personally know 2 people, who's from 2016 SPM batch, got successfully posted to Tampines JC and a her friend in Meridian JC
After they open to 2-5 scholarship a year, opened to ASEAN countries.
Both applied during their Form 5 year using their Form 4 results (All subjects are 90's A+).

You can try to apply, just note that you will be doing pretty much basically nothing the whole year except working or self study at home, or even you can be studying STPM while waiting to be admitted to JC1 in February 2018.

My advice is just do AUSMAT/WACE in INTI Nilai or Sunway or Taylors for a year, and get on with life.
I will not recommend doing A-Levels unless you want to study the subjects deeply for a better foundation.

ohh then go full steam ahead
just apply first, do google for IB scholarships and edexcels a levels one too ask your school counselor for help

ohh then go full steam ahead
just apply first, do google for IB scholarships and edexcels a levels one too ask your school counselor for help

IB is 2 years, tougher because you need to get perfect 7 for 6 groups of subjects both humanities and arts.
Go SAM for easiest route or AUSMAT for slightly harder route.

SAM -> AUSMAT -> A-Level -> STPM -> IB if I will rate it.