Wow, thanks for the nice feedback guys! (though Sonic Team really gets all the credit for their underrated graphics). I will definitely put up a download link as soon as I have finished Forest 2. The Skin will be available for Ultimate too!
To answer the question of if I will be doing more stages, you bet! Watch this space.
@Cyanide - one of my favourite stages! However I can't find my copy of the game, so I can't rip the textures. I would be happy to make that skin if someone were to provide me with a rip. If not, I'm sure I can dig my copy out from somewhere... Sonic Heroes only uses txd archives if I recall, so it won't be an issue.