Hello,
I don't know of a commercial skin package, there maybe some on snowcovered, but I don't know what the quality will be. I've noticed some state "CSS skin" when they are referring to 'we have styled this using CSS, but used tables for the layout' - so you have to be a bit careful when purchasing CSS skins.
As well as the red leaf there are these skins available on DNN Creative:
Which may be helpful, of course if you need help, you can always ask in this forum, thanks,