I remember back in Vanilla through Wrath there were 'addons' (they weren't really addons but it was on curse) that would replace the whole wow ui skin without using something like kgPanels. It was a zip you extracted to like Interface/Artwork or something like that.
Are those still around? Is there a good list of them even if it requires kgPanels to run. I looked under Artwork but that's kind of a junk FFA category.