Hello and welcome. I'm not sure were you are located but below is a link of some recommended testers originally posted by Grinity.

Psychologists who specialize in IQ testing for Highly Gifted Children.
And a list of Psychologists who specialize in IQ testing for Highly Gifted Children.
Also know to be useful in sorting out 'Twice Exceptional' issues. (2E)

http://maps.google.com/maps/ms?ie=U...5059822090.000461ba927f03f403bed&z=4