Corn meal, corn flake crumbs, and I bet, rice flour, though I have not tired it, would all make a good coating for nuggets. True deep frying may help as well. If you can do eggs, dipping in eggs or mayo may help too. Mayo especially if baking.
I am sure you can find low carb/paleo recipes to avoid the grains. Try using those terms in web searches. and Wheat Belly is a book about avoiding grains and has a companion cook book. I have not purchased it, but it may have good options, since it is all about avoiding grains in the diet.