I’d say it sounds like you’re on the right track for things to bring to a potential artist’s attention. Most importantly for a project that a writer is planning to pitch to a publisher is security for the artist so keeping this in mind, it’d be important to have a contract to insure both you and the artist are protected (they don’t steal your idea, you don’t leave them with nothing, etc.), along the same lines as the kill fee you mentioned. I’m not saying it’s something you’d need ready when initially meeting artists, but letting them know that there will be one if you and artist persue this project together will make it sound like a safer endeavour to look into.

Having some simple pictures of what your characters look like would be beneficial too, I imagine. Different artists will interpret characters in different ways of course but it’s always nice to see an example that you believe is on the right track of what you’re looking for! Images also provide an example of the mood your story is going for, which can help garner interest from artists. If you don’t feel comfortable showing your own artwork, you could always request or commission images from artists online.

Also, because artists at conventions are often really busy, you may not have much time to talk with them (I know I’m always really busy with selling prints at my AA tables so having longer conversations with people is hard at times unfortunately). I’d recommend posting the information of your story that you wish to share with potential artists online and having a business card, or something of the sort, to give to people so they can look it up at their own leisure.

Sorry I rambled on there for a bit! I hope some of it proves at least a little helpful. Good luck!