Kuala Lumpur is a great place to live with kids. There are some excellent schools, and the green spaces and climate are perfect for lots of outdoor activities. Our guide on living with kids in Kuala Lumpur has some good ideas of what's available for young families.
There are a variety of options when it comes to accommodation in Kuala Lumpur. Expats generally go for condominiums because of the pools and gyms, but free-standing houses are also available. Read areas and suburbs of Kuala Lumpur to find out which areas are close to international schools and have more family-friendly suburbs. Most of these are not that far from the city centre, but keep in mind that traffic in Kuala Lumpur can be an issue.
As to schools, you should start the enrolment process as soon as possible, because most of the top schools have waiting lists. International schools in Kuala Lumpur are usually the best option for expats, and there are many with the British national curriculum.
Hope this helped!
There are suburbs with detached houses in places like Mont Kiara, Desa Sri Hartamas, Desa Parkcity and further out in Valecia and Sierramas, as well on Ampang side of town. Google map will help you getting an idea of your daily commute - that will be a bit of a pain.
On schooling, yes, definitely contact schools before arriving, many have waiting lists and starting in the middle of the school year there will be fewer spaces available. Good luck!