@Nicobay I took the models from the latest game they came from, such as if I were to get Mega Latios, I would take the model from ORAS. What game the models were introduced is where they can be found. I also made skins for the different expressions + shiny forms.
Side note, what project should I focus on at this moment? I'm putting together a Sims 4 object pack. I could add to the Pokémon pack, work towards releasing what I can for Sims 4, or see if I'm able to work on an enhanced (read: NSFW) Pokémon pack (currently paused because of modeling issues).
I'm doing my best to get a solution for the enhanced option.