What type of pans to use would be determined by the size requirements of your cake. If you intend to make something greater than about four layers high, then you will need either a sugary "glue" to hold the cakes together. Another popular method for securing cakes is to position them, then drive a dowel through the middle, and or sides as necessary. But remember, if you are sculpting in three dimensions, then you will need to push any horizontal supports deep enough so that they won't get in the way when you shape the cake.
Also, you will need extra body in the cake, so that it is not so crumbly. To that end, incorporate extra egg white, beaten into a foam, into the cake batter before baking, as you would angel food cake.
Try to picture in your mind what shape you wish to create. Then, use pans that will allow you to stack cakes as you need to. And don't forget that you can use stainless steel mixing bowls to make domed cakes.
But remember, you have to alter your baking techniques to insure that the cakes are cooked all the way through. Use lower heat and longer baking times for deep cakes. There are also cake pans that have a small, hollow tube that runs up the middle, to help carry heat more evenly to the interior. My wife used to make a hooped formal skirt out of such a pan, for a Barby Doll dress made from cake. She was a very creative woman when she was younger.
With a bit of imagination, and some thought, you can pull this off. Good luck.
Seeeeeya; Goodweed of the North