I think Andy Lau would fit the role of LKY well.
He has played Lee Rock(五億探長雷洛傳: 雷老虎),
a film about the real life story of the reknowned HK police officer involved in the rise and fall of the corrupt Hk police force in the 60's.
In this film, Andy has experience in playing the role of an aged old man as well as a young hot bloodied guy with ease.
His next role as the two-faced police officier in infernal Affairs (無間道)
dealt with the conflict between siding with the underworld and the police force which he is in.
These films has the same setting and social and political dilemma that LKY has to dealt with during his tumblings years in the 60's singapore society.