well if i'm not wrong, if you intend to apply to SIA, then you
do your degree first. after that when you're at least 26 (min age
for singaporean male commercial pilots), apply for the SIA cadet
pilot scheme. You'll have to go through multiple rounds of
interviews and tests and all, and its rather stringent. Then if you
pass all of it, you will be sent for a CAAS medical, and then after
that you'll see whether they accept you or not.
You'll then proceed to do your fATPL groundschool and basic flying
training at seletar under singapore flying college with cessna
152s, then to jandakot in australia for CPL/IR/multi-engine
training on beech baron 58s, then more groundschool in singapore,
followed by simulator and line training at maroochydore (also
australia) with lear 45s, and you'll pass out as a second officer
from there, and assigned to either SIA mainline, SIA cargo, or
silkair.
Yep. This is as far as i know, anyone with better knowledge of this
correct me, thanks 
