Wow, quite an interesting style of drawing, very unique :-) Welcome on the forums.
The main problem when it comes to (specific) characters is that we're still going through a storyline discussion right now. As there are two rather different storyline proposals, we haven't fleshed out many characters in detail considering that they would work different in each proposal.
If you don't mind creating concept art for characters that haven't been officially approved yet, you can find a list here:
http://wiki.parpg.net/NPCs#NPCs_pending_approvalHaving some kind of concept art piece for one of them might seriously increase the chances that the NPC will make it into the game so I think you should go for it if you like :-)