You just need to know how to look. Most of them are here I think
First make sure they are not in these awesome packs by pixel pirate:
A-D: https://www.wincustomize.com/skins.asp?library=29&SkinID=1988
E-M: https://www.wincustomize.com/skins.asp?library=29&SkinID=1989
N-Z: https://www.wincustomize.com/skins.asp?library=29&SkinID=1990
Adobe: lots here https://www.wincustomize.com/skins.asp?wp=1&sort=updatedate&searchtext=Adobe&order=Descending&library=29
Ulead Cool3d: sorry haven't any good ones yet
Nero: lots
https://www.wincustomize.com/skins.asp?searchtext=nero&sort=updatedate&order=Descending&library=29
Goldwave: I never heard of this and I haven't found any yet
Scansoft: Again none yet.
If I find some of the ones missing I be sure to post them here