Private Adult Assessment Centre/Clinic with immediate availability/low Waiting list?

I am a 37 year old and have been referred on to my local NHS autistic assessment centre by my GP. The only problem is the waiting list for assessment is 33 months. My work health insurance will not cover aspergers, so I am looking at finding one myself. I personally hate uncertainty and would like to find out as fast as possible. Is there a list of private clinics that offer multi-disciplinary assessment for GP referrals in the UK?

Obviously, if anyone knows or has experience of a place that is responsive please let me know thanks.