I think the JW Pet toys are very chew-resistant, especially if you get the big ones. I call them Mr Squeakys but they are actually called "Cuz." http://www.jwpet.com/dog/cuztoys.html
Also a regular soccer ball is pretty durable. The dog will puncture it, but then they like to play with the leather shell.
I realize that I'm generalizing here, but as is often the case when I generalize, I don't care. ~ Dave Barry