I think if you are going to look for a spriter for your game, you should try a different approach.
Post some info to get a spriter interested. What are your intentions for the game once its finished? Are you publishing it to some manner of portal? If so, are you prepared to deliver profit sharing?
Because right now it comes off as "Hey, do all my sprites for me and Ill put your name in my game credits" and really, thats not much incentive.