I can see the idea behind the thinner camshaft seals as you can move the sealing surface if the cam has a groove worn in it by the old seal. That said, the thicker ones are far easier to get in and sitting square. I've had problems in the past with the thin ones not sealing.
35x47x7mm
https://fcpeuro.com/products/volvo-engine-camshaft-seal-1306333