[help] Looking for a pattern for a skirt (link in comme Sewing Machines Parts and Sales in Los Angeles

I’m in the process of making an ice dance dress and have looked all over trying to find a pattern similar to the one at the link below. I’ve searched dance skirts, skating skirts, and ballroom dance skirts. Does anyone have a lead on something like this, where it has the slit on the side? Or advice on how to draft my own?

http://imgur.com/a/k6Q6L