I like Anna's logic here. I've got a hard enough time trying to identify a yellowbelly so I would probably go with the super. Going with any super is a great idea because you can't get normals! You don't have to worry about what you're going to do with all the normal males you may or may not produce. Even though the other males has a chance at a lot of different combos, you still have the chance for normals. With my luck, I'd get half normals -facepalm-
Another thing to consider (I don't know if you have) is what the ivory's parents look like. Are they both good examples of yellowbellies?