What would be an appropriate gluten-free substitute for breadcrumbs? I would like to make a gluten-free eggplant parmigiana, and there are a couple of ingredients that I realize I will need to substitute.

The basic idea is eggplant sliced, dredged in flour, dipped in egg, coated with breadcrumbs, and fried, then layered with sauce and cheese and baked. It's the flour and breadcrumbs that I'm going to need to cope with here. I recognize that there's not necessarily one universal GF substitute for flour, but it doesn't strike me that this is so highly featured in this case that it will make a huge difference. I could probably omit it altogether, or use an on-hand substitute, like cornstarch. 

The breadcrumbs, on the other hand, are quite a vital part of this dish. I use panko breadcrumbs to give my eggplant an extra-crispy crunch. I've seen "breadcrumbs" make from corn tortillas used as a GF substitute, but the corn strikes me as stylistically opposed to my intent here. I've also heard of "thinner" coatings, like cornstarch or rice flour, but this again fails to capture the nature of a breadcrumb. 

Gluten does not strike me as a particularly vital element of a breadcrumb. It is quite unlike, say, a bagel, which is founded on the properties of gluten. But theoretically, I suppose you could make a breadcrumb out of gluten-free ingredients. So what are my options?
There are a number of rice-based bread crumb replacements, but my experience with them is that they are more like rice sand than bread crumbs.  You can try making you own from other gluten free products like waffles or maybe puffed rice cereal.