What constitutes, or is there such a thing as fair use of a copyrighted logo?
Even if you are just using the item with the copyrighted logo for personal use, it is still considered copyright infringement. The copyright law is black and white – there are no gray areas. Therefore, by not getting authorization to use the logos on the guitar picks, even for your personal use, you are violating the copyright law. The best way to move forward to get your guitar picks is to seek permission from the organizations that you are using logos from. Or, find a manufacturer that already has permission and can print them on the picks for you. Sources: http://en.wikipedia.
No, there is no fair use of copyrighted logos. You are simply not allowed to do so, and the manufacturer might even be breaking the law if he were to help you. A logo copyright is for any and all reproductions, so if you want to use them, you need to contact the owner of the logo, asking permission to use it (free or for a small fee).
