Welcome! Your son sounds like a very nice and gifted child. At the age of 4 your options are quite limited. The most common are WPPSI and SB-V at that age. There are other tests available (we were offered a different one but I forgot the name of it). Reading about your child you definitely want to take a test accepted by Davidson Young Scholar program, which would be either WPPSI or SB-V.

You can check the list of recommended psychologist on the Hoagies site. The waiting list for those may be quite long though or you can see if there is a gifted center near you. Not all the testers offer all the tests.

You may consider achievement test in the near future. That one may work better when it comes to the school administrators. They may understand Broad reading score better than VIQ.

LMom