I applied to the PhD concentration of Autism/Developmental Disabilities, but I don't foresee too many differences in expectations between admission committees in each concentration.
You have an excellent and very rigorous academic profile. I think you would be a potentially competitive candidate for admission. On my side, I have more of a research background (research assistant on a special education grant, independent research: one article in process, one presentation), but I do not have any teaching experience.
My SOP was based on my background in working in the autism field, being a Master of Social Work student for the past two years, and how these experiences have shaped my research interest/focus. I would highly suggest writing about teaching and the development of inclusive curriculum in Kazakhstan; these experiences would help you stand out as an applicant and depending on your career/research interests will be relevant.
But of course, get in touch with the department first! I'm not sure how far along the admissions committee is, but you never know. I submitted my application in the beginning of January, past the priority deadline, and within the next couple of weeks I read my application had been 'submitted to the Graduate Committee for Review'.