PR application for my son

[cr3zy]

Hi All, would like to seek opinion for PR application success rate for my 5 months old son born in Malaysia, our background as follow:

1) Both of me and my wife are Malaysian Chinese (SPR) aged 29 yo working in Singapore
2) Both of me and my wife are Singapore Chartered Accountant worked as auditors with monthly income of 5k each
3) I worked in Singapore 6.5 years (2.5 years under EP and 4 years under PR), Australia Degree
4) My wife worked in Singapore 3.5 years (1 year under EP and 2 years under PR, Malaysia Degree
5) Me and my wife's PR were applied separately
6) I will be the main sponsor for my son application
7) Do I have to apply LTVP for my son first or straightaway apply PR for my son?
8) Another question, is it possible my wife apply Singapore Citizen with my son but I remain as SPR? If yes, what is the success rate?

Thanks in advance