If it's a tester you need, Grinity recommended Aimee Yermish to us. I haven't had the pleasure of speaking with her yet, as recent times have been full of work emergencies for me. My wife praised Aimee's apparent expertise, perceptivity, and horse sense, and said that she is obviously focused on the child's needs instead of being a money-grubbing hustler with a degree.
YMMV-- she may well be a money-grubbing hustler-- but I don't think so.

She apparently spends a lot of time interpreting the testing results, and can also serve as an advocate with the local school system.