Ichthux is an additional package in the Ubuntu repositories, so, as such, there are no downloads available.
Procedure to install Ichthux

1. Download Kubuntu
2. Install Kubuntu on your computer, in your preferred configuration
3. Open the Adept Package Manager and do a search for "ichthux-desktop"
4. Click the Request Install button, and then the Apply button.
5. Logout and log back in to your new Ichthux desktop!