I think i got a funky one from Emblibrary.com I think it was called on the wild side. Just put guitar in their search box and it should bring it up. I was going to put it on an 18 yr's old t-shirt. Found it!!
just remember how much detail would be required for this design and it does take lots and lots of time to digitize. You may be better off purchasing one from a reputitable site for much less. Good luck.
Here is a free guitar at Tex-inc.com