The official site is best for lips graphics:http://www.rockyhorror.com/downloads/
Look toward the bottom, in the Wallpapers, Exclusive Posters, and Logos sections. Some of the images there are huge. None of them are on a white background since well... they just don't come that way. The one I used in the top left for the forums was created in Photoshop by taking one of the larger "poster" images, masking the lips and Frank off from the black background, and then pasting it onto a white or transparent background in a new image.