I can't give you an exact address for a higher quality version, but I can help you find one you're happy with.
If you search via Google Images, they have a new feature where you can search by using a picture you have. As you look at the search bar, at the very right end is a pic of a camera - click it. Then you can either input an URL for the picture, or choose to upload it from your computer files.
Google will then search out this specific pic and compile a grid listing of all the versions it could find. To get to the listing for the pic, you'll need to click on the thumbnail of the pic at the top of the search results page. You'll be redirected to the different versions of the photo you searched for.