Hi!! I was asked to make this cake and was looking for other advice about what kind of structure to use? Thank you all in advance!! :)

AI would use a threaded rod, drilled into a wooden base with PVC. You will need to plan ahead very well. This is a large project, you should also consider how youre planning on traveling (if need be). Big project if you've never made a cake with an internal structure! Cool idea!

You need this sort of structure, but on a higher scale!

http://jessicakesblog.blogspot.com/2010/02/princess-dress-form-cake.html

http://jessicakesblog.blogspot.com/2013/10/strawberry-shortcake-cake.html

Thank you both so much!! imagenthatnj -I was thinking about doing something like the first post you sent. with the flange and plywood! I think it will hold it up but I just wanted to see what everyone else thought too!! Thanks agian!