Autism spectrum screening and speech therapy for 2YO

Hello. We are seeking recommendations for two types of medical services for our 2-year old. The first is for a specialist who can perform an autism spectrum disorder (ASD) screening (e.g. developmental pediatrician, child psychologist).  The second is for a speech language pathologist who can supplement our son's existing therapy and who has significant experience with developmental delays and/or disabilities.  We are based in Oakland but willing to travel. Any tips or advice would be most welcome (I already have screening referrals through Kaiser and to our Regional Center).  

Thank you!