If you can use couscous as a coating, semolina should work well, too.
I don't do a lot of coating on foods, since we don't fry much and my wife is trying to stay on a low carb diet, but panko stays crisper than bread crumbs. (I've used it instead of cheese on the sides of the dish when doing a souffle.)
Panko has the advantage of having already been cooked, semolina and couscous are both still raw durum wheat and probably wouldn't work well in a dry cooking environment, they need to have water or oil available to soften them.