Have you considered making this a general purpose ribbon plugin, i.e. for any kind of diagonal advertising banner?
The only customizable plugin I could find for this was last updated in 2010:
On a slightly related note, I did try editing the plugin for my own purposes. I'm no coder, but it was easy enough to do some search-&-replace to alter the preset text. Where I got stuck was with WooThemes' responsive Buro theme. I got the plugin working with the default WordPress themes as well as another WooTheme, but I suspect the plugin failed on Buro because of its responsive design. Anyhow, I'll see if the WooThemes developers can lend me a hand.