I am not at all sure how your planned living arrangement will work. Is your husband going to be based here or in Shanghai? If he is not going to be working here, he won't be getting an Employment Pass. Which means you won't be getting a Dependent's Pass to live here. While I have no doubt that Singapore is a far better place to bring up kids than Shanghai, from the sounds of it, I don't think your plan is feasible.
Moving on to your questions. Staying in a
condominium (with communal facilities like a swimming pool, playground and gym,) will set you back a minimum of $3k to $4k a month for a 2 bedroom apartment. In your personal circumstances, with your husband overseas so much, don't even think about going the HDB route. (If you don't understand the terms I'm using like
condominium or HDB, please use the search function here. It will save you a lot of frustration and confusion.) in terms on
International Schools, the search function will answer your queries. But, since your eldest is only 4, I don't think formal schooling is an immediate concern.
Frankly, I don't think your plan is workable. Even assuming that you can live in Singapore while your husband works in Shanghai, this not a wise choice to make. 1, you are already worried about loneliness while he is away. Expat wife loneliness is already a big problem when the husband is in the same country (just check the search function for this). It will be infinitely worse if he is not really based here. 2, let me be very blunt. Shanghai will have a LOT of temptation for your husband. I'm sure he loves you deeply and is totally loyal to you. But you are still asking for trouble if he spends so much of his time there without you and the kids.
If your husband is dead set on working in Shanghai, then you should be moving there. Not Singapore.
"Both politicians and nappies need to be changed regularly, and for the same reasons."
