This website contains a handy list with photos and a search function for available Virt-A-Mate celebrity characters:
https://virt-a-mate-list.netlify.app/
Most of them are paid, but you can get/request them here for free:
https://f95zone.to/forums/asset-releases.95/
https://f95zone.to/forums/asset-requests.96/
All of them are designed for Virt-a-Mate, so only in Genesis 2 format. Diffuse textures are usually 4K or 2K, sometimes without normal maps and almost always without Displacement/Specular/AO and other fancy things from Daz 3D.
You can use this portable, simple program to convert VAM .vmb morphs back to .dsf morphs that Daz 3D understands.
https://hub.virtamate.com/resources/vam-to-daz-2.888/
I know that only the oddballs from VAM community use the forgotten and futile Genesis 2 these days, but if you really need some celebrity character, converting morphs/textures from Genesis 2 to Genesis 8 will be faster and easier than sculpting everything from scratch.