Excuse me? I'm sorry but your rules state that the character becomes your property once the winner is decided. You CAN NOT own any character made from a Base DAZ figure no matter how you wish to word it. You'd better check with a lawyer on the wording of your rules if you wish to allow DAZ characters into the contest, or any other premade geometry based characters for that matter. No winner will be able to send the geometry to you for figures that are not redistributable. Period! End of Story! If they do, both you and they will be guilty of copyright infringement!

Winners of the 1st, 2nd, and 3rd-place prizes further agree to deliver and grant full rights to Humanity Online LLC to own and use the full 3d character, including all source files and textures needed to create the character, hair, and clothing. The winning 3d characters, as well as source and texture files become the property of Humanity Online LLC and the artist conveys all rights to Humanity Online LLC;

I'm smelling a scam! 

It is a miracle that curiosity survives formal education. - Albert Einstein