In Phoenix I have heard good things coming out of Melmed Center. They do diagnosis, only. However, that IS one of the services that are difficult to find for adults. They do diagnosis for both adults and children, and you have a choice between a doctor and nurse practitioners, depending upon how long a waiting list you can tolerate (2 to 5 months). I have not tried them, yet, but after trying a few independents who list "autism" as a specialty, I am thinking that it must be WAY better to have somebody who specializes in autism.
Also in Phoenix, the Southwest Autism Research Center (SAARC), has some services for job habilitation for adults with a diagnosis. They list some therapists who provide social skills workshops for adults, mostly teens. And the Clinical Psychology Center at Arizona State University also does some social skills workshops (10 weeks at night) for adults. There are some peer support groups that can be found on Meetup.com. AZ has limited financial services thru DES-DDD for adults diagnosed with Autistic Disorder (AD), if they can document that they "had it as a child", which is pretty ignorant wording, if you ask me. What I have heard from insurance so far is that a law mandates coverage for children but adults may be restricted from ALL behavioral health coverage once they are diagnosed on the spectrum (weird and I do not understand it yet).
Finally, vocational rehabilitation thru DES can "work miracles"; however they are extremely bureaucratic. You have to qualify as either highly or medium disabled (4 or 5 deficiencies on their list of , wait for approval and funding, show them that you are employable from the beginning, show up for every appointment, do "everything" they say, and it is hit or miss as to how understanding your counselor is, but they do have good resources that can help you get stable employment. This is advice from a counselor who told me about it.