K - it sure is true that if the school system will do the testing, then they are somewhat more likely to believe the results. OTOH, the point of testing is to give you the parents some idea of what to ask for - so if your DD is Ruf Level III or beyond, a local tester is unlikely to be very informative.
Reccomended Step One -
Decide what your goal is. If it's a grade skip, then you are going to want individualised IQ testing at school or privatly. If you want to learn more about your child - Deb Ruf's book, Losing our Minds, and then school testing or private testing, how much travel depending on where you think she fits on Ruf's estimated Gifted levels.
Best Wishes,
Trinity