Just Bento

I like the recipe on just hungry for lentil snacks, but I can't have wheat gluten anymore, so bulgur is out.

I need a substitute for it, and I was thinking about cooked brown rice. It's a little nutty, which I think would replace what might be lost from the bulgur.

Does anyone who's familiar with these have any ideas about alterations to make them gluten-free? Does the brown rice sound like it would work?