There are a number of schools in Kuala Lumpur that will fit your criteria. Have you tried contacting any schools directly to see if they will be able to meet your child's needs? Have a look at the Expat Arrivals list of international schools in Kuala Lumpur to find the contact details of some of the schools in the area.
Yes, there are International Schools that do provide learning support in terms of catering to specific types of learners from basic to advanced levels.
British School of Kuala Lumpur is one of the best schools providing the support. International Schooling, which offers an American curriculum will also suit well if your son is pursuing secondary school education.