Dear Contest Holder, for your own interest ask entries on a plain white/black background as well, because those 3D effect/mockup/background things just trick your eyes, and they don't show their real looking, not even their true colors when you want to use it on a business card, website etc....
100% editable according to client's need.
Any changes you want in colors or fonts muckup anything else is available for you. I will provide you all photoshop services and illustrator you seek.
( AI VECTOR, PDF, EPS, SVG, PSD, JPEG, PNG TRANSPARENT BACKGROUND )