Welcome, galun!

Here are some further thoughts on whether to test -
Testing your gifted child: a springboard to advocacy (Duke TIP, August 2006).

A good starting place for finding a tester is Hoagies Gifted Education Page, which includes a webpage listing Testers.

For information on testing, see this old post from a thread whose subject is What do you tell your DC before IQ testing?
Other posts on this topic include this one from a thread whose subject is Help! What do I tell him about the testing?

You'll find a collection of advocacy resources and threads here.