I plan to use my sports ball pan for the main part, but for the side supports I'm undecided if I should construct them out of cardstock (which someone who posted on the galleries did), cake, or fondant?

I plan to set the ball onto a smaller piece of cake to raise it up slightly, perhaps putting a dowel in (though I've never doweled anything before). I don't feel the supports will be needed for actual support, but they need to be there to make it look right.

This is for my parents, who are coming into town this week. They are Disney lovers, so I want it to look nice!!!

I would use gumpaste or add tylose to the fondant so it dries in time. But card stock would be the quickest.

I actually have gumpaste that I bought for something else but never used. Interesting idea---how far in advance would it need to sculpt those before I paint them gray?

I would use rice krispie treats stacked and shaped like the pillars and then cover in royal icing followed by fondant.

Paul