There are some galleries in the Tutorials and Galleries sub-section, but they are somewhat few-and-far between.
Tutorials and Galleries:
http://forums.d2jsp.org/forum.php?f=246Instead of creating gallery topics, many users have been posting their works in their personal photo galleries. Although these signatures may not be exactly what you're looking for, they'll give you a good idea of overall talent and style of the artist.
Premade Signatures:
http://forums.d2jsp.org/topic.php?t=69806439Lastly, since you do seem to have a preferred image in mind for you signature, I would suggest posting a graphic request. This would allow other users to submit various attempts, and it would likely result in the widest array of potential outcomes and styles. If you find a specific graphic designer that you like, via their service thread, then that could be an option as well.
Graphic Request Forum:
http://forums.d2jsp.org/forum.php?f=111Hopefully that clears it up
