hhbella - I really think that the hoagies chart is off in this regard and you should consider the Gifted minds chart as accurate. Like Gifted Minds, the DYS program also considers the SB5 and WISC to be equivalent (ie 145+/99.9%+ is required on either test).
With regard to his WISC scores - do you have percentiles? If you post the percentile ranks here for the FSIQ or the various indexes, chances are that someone will be able to convert them to numbers for you with reasonable accuracy. The Australian norms are slightly different to US norms but not dramatically. It's common practice in Australia, not just in schools, to only provide parents with percentiles and it drives me mad too.
With regard to the grade skip - my own DD is skipped, it was clearly the right choice for her, though we are now entering her second year it's already "not enough" and I am not sure school are aware that they need to step up and start extending... Anyway, the point is that I am definitely open to skipping. The only caution I would give you is that to my inexpert eyes your DS strongest area is Knowledge. Roughly speaking the Knowledge section tests what he has learned (and a score that high reflects what a gifted child in a rich environment can learn). His Fluid Reasoning is high and solidly gifted (optimally gifted you might even say), I would not hesitate to skip him if school is seeing what you are seeing (which it sounds like they are) - but it is possible that he stands out more now as a young child than he will a little later on. Or he may continue to stand out, he may always have knowledge as his strength, this can in part be related to personality - if he's gifted and has a personality driven to collect knowledge/information/data/ideas then he will likely always be strong in this area. Again, I'm NOT a psychologist or expert, take it with a grain of salt...
My own DDs weakest area was QR, which is also quite influenced by acquired knowledge/exposure to content. The tester felt her slightly lower score in QR could be accurate, and that she had a relative weakness in this area, or could easily reflect that at 5 she simply hadn't developed an interest in math or had much exposure (she hadn't had any really) and that her QR score might shift over time.
