Moving to Kuala Lumpur

Good Day, everyone.
I'm Zaara, currently living in Kuwait.
I'm moving to Malaysia next year and would like to know and learn about Malaysia, as much as I can, before actually moving there. So, here I am, I need you all to help me out a little.

I'll be moving with my family. Me, my husband and my two children- son, 7, and daughter, 15.

1) So first, I'm a bit confused thinking about where to settle down.
My son is suffering from IBD. His pediatric gastroenterologists are available at UMSC and Sunway medical centre, both are in PJ, so I was thinking to move somewhere close in Selangor. Unlike Kuwait, Malaysia is very big and there many places to choose from.. so which areas do you guys suggest? I'm not looking for places with luxurious, fully furnished condos with swimming pools, bars or nightlife etc, but high floor, medium rent apartments, unfurnished with balconies or big windows, and parks, grocery shops nearby.
Which areas has new apartments in PJ or KL?? I visited Damansara Perdana this year, most of the condos/ apartments there seemed to be quite old. How's Kajang??

2) Cheap Schools following British curriculum? I've searched on net, most of the international schools in KL seem to be really expensive. Tanarata International in Kajang is affordable for my daughter's A levels, but for my son, I'd like to try and search a little more, as he's still young and its okay if he studies in different curriculum for a while.

So, let me know if you guys have any ideas. Thanks in advance!