You can find an Eku form on the first Kobudo video from Tsunami productions www.dragon-tsunami.org. It was, I believe, done by Matayoshi sensei from Okinawa. Have not seen the Panther video.
The panther video is good also, it is also matayoshi style though so one or the other on that both are good. Really I would find a good kobudo instructor to teach you a eku kata though. Eku is one of those weapons that is pretty unique and Sensei Sony is not the best teacher imho and really should be a second step option.