With Zazzle allows artist to create any product with our design on it. Personally I think you should tailor your image to the product you have in mind. Yes, it may take longer that way but I feel it is in the designer's interest to keep the quality high. For example
I thought of all my Zombie Christmas card images the perfect one for a photosculpture was the most recent due to its composition. I altered the image slightly and added a black line to clearly demarcate between the body of the sculpture and the area I want to have removed.