Although rice isn't ideal for cats, it probably won't pose a problem unless he has an intolerance for it. I suppose you could try it and see. You might want to mix the rice-containing formulas with some totally non-grain food and increase the percentage of the new food slowly, at least the first time, though.
Keep in mind, though, my experience is with food sensitivities in dogs, not cats!
Still, a slow introduction and close observation seems like a good strategy...