High-Res images for Custom Skins

Hi ...

I have a white M6 and want to design a custom skin, the one the ebay member "eacoskins" makes for the player.

Does anyone know of a website where I can find free, high-resolution images that have a TRANSPARENT background??

Is so, please let me know. I need high-res images with transparent backgrounds (or at least white background) ... to create a good custom skin.

Thanks.