Without code shares it would be QF SQ CX or MH with transfers in SIN SIN HKG and KUL respectively.
BA to SIN and BA code share on QF to PER
AY to SIN (via HEL) and AY code share on QF to PER
and maybe
JL to SIN (via NRT) with a code share to PER.
Which of the OneWorld partners would have the best mileage/status crediting to support your CX Gold account?
Happy wandering
Fred