Hello guys; sorry for reviving an old thread, but i just wanted to add. I also wanted to use the Oxyslack splash and found the download link broken. (I googled it which is how i found this thread).
Either way, i've sent an email to dgazzarri, and he's now fixed the download link and Oxyslack is now downloadable. Additionally, dgazzarri also added a new splash theme at the same time called, SlackLinuxEvolution.