I guess that amount would be easily enough. Of course it depends on your way of living too. If you always go out fancy restaurants and choose a very expensive condo
, nothing will be left.
Starting from 3k, you can find convenient condos
near MRT stations. If you won't have a car, being close to an MRT solves your travelling problem. Just to give you an example from myself. My office is in Tanjong Pagar and my condo is located in Clementi. My condo is 8 mins walk to MRT station and my whole journey doesn't exceed 35 mins from condo to office. If this time or a little bit more is acceptable in your standards, you don't need to live very close to city and can save some money from condo rent. In fact this will be the major cost.
As your children are small, you don't need to think about education costs yet. Staying in a condo wil also help your wife meet with other expat wives and socialize.
Your salary package sounds good, but your comfort here will depend on how much you want to save out of it.