If you are trying to get PSA-9 of each Ninetales, that means only English and Japanese ones are possible (and the other languages for the Base Set of course). In that case the Ninetales TCG page on Bulbapedia is indeed the best source, where you can open each individual link in the Card column to see all Ninetales cards and information about their release.
As for (gradable) cards outside of the regular versions:
- The No Damage Ninetales error that was only available on the non-1st Shadowless Base Set print run indeed comes to mind (which you already mentioned)
- Another Ninetales misprint is the Cracked Ice Holofoil HeartGold & SoulSilver version that came in the Stage 1 Blisters, which were misprinted with the Undaunted set symbol instead of HeartGold & SoulSilver set symbol (although this particular print didn’t get a corrected version, so all Cracked Ice Holofoil versions of this art have this misprint)
- Thin vs Thick 1st edition stamps for the Base Set Ninetales, and maybe also Grey if you can find it (here an article I wrote about all 1st edition stamp variations). Here an example of the Raichu as Grey Thin; Thick; and Thin stamps from left to right.
If you ever decide to collect all languages, lmk. I make lists for single Pokémon collectors pretty often, and have already made almost 90 lists thus far. EDIT: Actually, it seems I have already made a Ninetales list in the not too distant past (June 9th, 2019). 
Greetz,
Quuador