G'day mate! Sorry, couldn't help myself
Nothing is very far in Singapore. There are plenty of good schools to chose from. Eton House, Chatsworth, Rosemount are the smaller schools that spring to my mind and then there are larger schools which would cater to your children's ages.
How good of a pkg. will you have? Will they be picking up the bill for education, housing, etc? Will you be getting a car? These are all things to think about. Housing prices are on the increase at the moment, so if you have some help, great!
There will not be a beach similiar to what you have grown accustom to in Sydney, I miss my beach walks, too. (Sunshine Coast) There are some
condos which do have a patch of green garden, but those are difficult to find. Most
condos are family friendly and the children will be safe.
Google for schools, housing, and find out where your husband will be working from. Look at a map of Singapore and get a feel of it. My children are teenagers, but it still was a hard decision. Good luck and keep asking those questions!