As I understand all expat allowances (school, housing) were taken away a couple years ago, I looked into SIA cargo a few months back and my numbers considering the cost of living in Singapore simply didn't add up, you could try and live in Malaysia and commute to SIN to lower the costs but otherwise is just not possible to live there with a family and a couple of kids, don't get me wrong, Singapore is a great place, clean, safe, it is called the garden city and the name fits it very well, I wouldn't mind living there if the allowances were restored, but Singapore's charms come at a cost, you will be paying upwards of $100,000 SIN dollars ($80,000 USD) for a Toyota Camry, a beer will run you 25 sin dollars, phone, electric and gas bills are outrageous, more expensive than even Japan, and rent for a three bedroom apartment large enough for a family of 4 will set you back $8,000 Sin dollars
and let's not even discuss how much you will have to dishout for school for the two kids
