Why is that cheating? That's what royalty free images are for, silly! Especially if you want to use it for something like that website. But, that's up to you. If you want to create a chess piece and make it artsy and your own, the more power to you and I say GREAT!
But if you're complaining/whining about not being able to do it (saying that your imaging skills suck), etc. then my solution to you is ... just use a royalty free one.
Either, do your best to create one, or use a premade one and do your best to make it look good on the site.
You're gonna need to become a more positive thinker, mussavcom