Hii there,
You can visit
http://www.sfcpl.com
I think SFC is starting to recruit private candidates... some of the airforce retirees are taking the ATPL at their own cost.. But they had been guaranteed a place in SQ once they complete... But there's no guarantee for ab-initio private students... And the fee is not cheap....
Furthermore, even if you manage to get a frozen ATPL, if there's no airline willing to give you a type rating.. the ATPL can be deemed worthless...
Don't give up my friend, apply to SIA again and do more read-ups before the interview.. I trust you can make it with your passion and will-power...
Just my 2cents worth.. hope it helps.. =)