I’d be more careful about quinoa but its worth trying out. I couldn’t digest it personally but I also had very bad leaky gut and was highly allergic to it. The rice should generally be OK, especially if you rotate the types of rice you eat (brown, wild, jade, red, black, etc). Keep in mind to not eat each one of these daily (in other words 7 days a week don’t eat rice, but maybe 3-4 days eat rice and 3-4 days eat buckwheat).
And chew it thoroughly and then it won’t ferment in the gut.
Rice is a prebiotic and is generally safe. When starting out we need to be strict but as you progress, its less important. I only get strict when I want to bat down the yeast temporarily for a few months and then let it come back again.