You probably shouldn't say 'artist for hire' if you're not going to pay anyone. But is this going to be a collaboration thing where you and the artist reap whatever profits you make from the comic equally?
And also, it might be a good idea to give everyone a brief idea of what sort of comic you want to make. If you're worried about people stealing it, for whatever reason, you don't have to give away enough that that would be possible. But at least give a brief idea of what the story, setting, style, tone, whatever is to get people interested.