Hi, Jason: You may want to try contacting either Philip Norman through his website; the publisher, HarperCollins; the graphic designer, Jessica Shatan Heslin of Studio Shatan, Inc.;, or even the photographer, Bob Gruen. I don't have time right now to chase down the URLs, but I'm sure they can easily be found online.
HarperCollins might be your best bet, but definitely try to contact an individual, probably someone in the copyright department. Your best bet of tracking down a high-resolution print lies with the copyright holder.
Alternatively, you could track down a printer/graphic artist and ask them to mask the text from a high-res print of your own, as long as you don't try to profit off it (i.e., sell it).
Good luck! It is a great photo.
