Will u also consider Tutor-time? My baby is now taking their toddler playgroup and they have a native english/mandarin speaking teachers teaching the language. One of my friend's daughter studied their pre-nursery class for 1/2 yr and her girl is able to speak quite good mandarin.
HKPS kowloon tong is really good. worth of money. many grad. goes to famous school, yan Wah, DGS, kln tong primary, st. paul co. ed. During k1-3, they employ professional outside to teach the kids, musical instruments, eg, violin, africa drum....., sports. two master, chinese and foreign teachers all the way thr. K3. they also help parent to do profilo, provide free interview training class for the kid. have a look at their web site.
They promote and encourage readings at the kinder. All the kid study happily. The only disadv. is that the admin. office is a little mess.