Hey guy and gals..... I just checked CG Textures and they provide free (you do need to register) 3D scanned objects (in obj format) plus the three main textures you need for the principled shader....quick and easy to use.... see below....I plugged and played and it worked fine then I added the subserf and will now tweek as needed....also check out their free sculpt brushes...takes awhile to get them using their free access but worth the wait to build up your library....
If you want to pay a little I would highly recommend Rock Essentials....see Blender Guru on youtube...
