If you're looking for an in-depth diagnosis, I'd recommend a neuropsychologist. If you're looking for treatment of symptoms, I'd recommend the speech language route.

I was convinced my son had dyslexia, and the neuropsych eval revealed dysgraphia and ruled out ADHD. So getting the right diagnosis helped us address his challenges quicker and more appropriately. While speech therapy was a part of the treatment, it also included OT and PT as well.

~Lisa
http://www.lisaabeyta.wordpress.com/