Try the local LLL or AP International for recommendations also. Also, inquire if they studied under the Gestalt approach. According to a psychologist on the Always Unschooled list "The Gestalt approach dovetails nicely with child-led living."
Personally, I have found counseling a resource for myself. But, I'd seek someone who may not *have* children of their own. My counselor didn't; and she was very open to hearing about alternative parenting, without "defending/imposing" her own beliefs. Since she didn't have any parenting practice in conflict with my own, it was easier for her to "allow" consensual parenting.
My impression is that parenting creates a lot of personal defensiveness, even among professionals. So, someone who understands the theory of respecting children without the "reality" of the challenges of doing so 24/7, may be more of a compassionate resource for your son. In other words, they don't bring their own parenting paradigm and baggage to the table. We all have our philosophical filters, and those who learned the theory of validating and reflective listening without dismissing the child's experience and trying to manipulate *him* to change, may be more effective at meeting your child where he is and allowing him to voice any wounds and fears openly.
How does your son feel about visiting a counselor? Have you all considered family counseling as a supported process of giving you the tools to support him? I really love the NVC tools of communication. This article about "Compassionate Connection: attachment parenting and non-violent communication" is a favorite of mine: http://www.cnvc.org/motherin.htm
You might consider printing off some articles from Jan Hunt's site at "The Natural Child Project", and sharing those with a potential counselor. And see what their reactions is. But, if you enumerate that you AP, coslept, CLW, non-punishment oriented (or whatever) and they were like, "Boy, I can help you fix that!", you'd know you were on different planets.