How to get a GF Foamy Head?

Going to be brewing all grain GF IPA soon.
On hand: chestnut chips, millet, GF oats, buckwheat, amaranth and quinoa.
All grains are malted (except chestnuts and oats).
Will any of these help with head and head retention?
Heading powders are not GF.
Going to use Centennial Hops like Bells.
Wondering if gluten itself is the foamy wonder?

There are many factors to head formation. Yes and no to gluten being the head formation. Gluten is a protein and protein is a main proponent to head formation. Amaranth has loads of protein. Everything you listed, except chestnuts, can form a head. Maltodextrin can really help. It is gluten free in 99% of cases.

I recently made an IPA with mostly millet, a bit of amaranth, quinoa, and .5# of maltodextrin. It has a great head on it.

Thanks for the shout back.
That's good to hear. Looking forward to
Experimenting the next two weeks.

I get great foamy head from Fawcett oat malt. Nobody knows exactly how much gluten it might be contaminated with, but many are fine with it. You can search for some discussions around here about it.

In my experience head and mouthfeel are fine as long as you use a decent amount of grain and add some maltodextrin.