If you want the old school icons:
Download
Default Old and use that as your UI
or
Download
Default Old and only copy the following files to a new folder to use as your UI
gemicons01.tga
gemicons02.tga
gemicons03.tga
spells01.tga
spells02.tga
spells03.tga
spells04.tga
spells05.tga
spells06.tga
spells07.tga