soy isn't good and should be avoided.

Nature's Variety by Prairie is good too and they have a grain free kibble now. It uses tapioca or something like that
http://www.naturesvariety.com/content.lasso?page=1352

but if price isn't an option I'd recomend the freeze dried. I give that to my dog when she's ill and wont eat anything else. And they don't have to put as much carbs(grain) in it since it's not a kibble.

My cat is doing good with neem rubbed in and occasional washing.