You might consider contacting a pro like a golf course superintendent or university campus landscape supervisor. Sometimes, they hire arborists, and they care about who they hire.

You could go to http://www.isa-arbor.com - click to enter, then on the menu select the option to find an arborist. Then enter your zip code to find a Certified Arborist.

If you don't want soliciting, tell them up front. And let them know you don't want free advice. That way you are paying just for consulting.

There are consulting arborists that just do consulting. Often, their niche is indicated.