I'll give my three about a heaping teaspoon (total) of brown rice (much healthier than white) cooked with no salt. This is very seldom, maybe twice a month. Don't overdo it, it's way
backward on the calcium:phosphorus ratio -- 0.125:1! Not as bad as corn, but not great.
As for fish, any good fish is okay as long as it's very well cooked. Of course you know to avoid canned or pouched fish prepared with salt, like tuna or salmon. Fresh salmon is a good protein, and my guys love it. They also love shrimp, talapia and sea bass. (Not so crazy about catfish, however; but I don't blame them, it's only good fried.) Quite often I'll squeeze a little lemon or lime juice over the fish, and they like that too.