Your gonna find this weird but the biggest resources of Bryce Textures is actually within Bryce itself(I will explain better than this)

You can make Endless Textures with so many different Methods for Example Using Boolean objects to make things then turning to aerial mode(from Above) and you can make loads of textures that Way or another way Copying Bryce Textures from an Aerial View and mix and match them in Photoshop(or Gimp or Whatever). and you can make endless Textures That way too. So in my View the biggest Resources of Bryce Textures is already within Bryce itself all you need to do is a little experimentation to get it.

Karl