My kids did WPPSI and WJ-III with a nice pleasant psychologist who doesn't specialized in gifted children. The wait for the appointment for short, the report came quickly. She was a pleasure to work with.
DS5 took a SBV with a psychologist who tests lots of gifted children. I wasn't that impressed with her. It took forever to get the results, even longer to get her correct some of the details (like consistent spelling of DS name). There were a few more glitches. I was far from being impressed by her.
If you feel comfortable with the local tester than do it. It may also put less stress on DS8 than traveling (not sure how far you live) and all that involved.
