For scale figures you just have to scour different toy lines and compare photos to see which comes close enough. This anon is right, the Tomy Battle figures scale amazingly. Their Greninja, Machamp and Alolan starters are some of the best articulated Poké figures. The Figuarts/D-Arts are worth having too I think, because of their articulation and how nicely they're made, they look lovely on display.
The occasional WCT, Jakks or Hasbro also scale as well. WCT's Dragonite and Gyarados are amazing big figures, whereas their Lapras is pretty small, but there is a super rare Tomy DX out there that's a great size. You'll find you just have to mix and match and there's random ones out there. Let us if there's anything specific you're looking for and we might be able to help.