I got an order for a cake to be a 70s platform shoe. I need help on how to create this.

Which cake is the best dense cake to create this? How can stand the heel and toe part of the cake without support in the center? Below are a few pictures I drew out of a picture that she sent me. Please help!

Hi, have you considered using a thick 1/2" piece of foam core board covered in fondant for the insole, it would top the heal portion and be the top of the toe portion also. Then you could have the straps done and dried right on that part of the shoe. Then it's just cake that you can dowel into the foam core board. You would need to bend it a bit to get your shape and prop it up to those heights when making and drying, but I think it should work. Good Luck.