When I had a kiln at my disposal, I had a press mold for ceramic 'half heads'. They weren't fancy, just about 4mm thick clay, glazed and fired. Glaze is a form of glass, so they were great for helmets of all kinds. The one in the photo is for a tanker helmet. Cheap stands were used, but I also use glasses and other items that will work. I like to have my stands so the Pickelhaube's visor is about three millimeters above the surface. That way, I can lean it forward just enough to touch, but not rest. It keeps the visor trim from thinking it can slip a bit.... it all depends on the helmet.
Anyhoo, I NEVER use styrofoam heads, even (for me) with a barrier. I've seen styrofoam and foam rubber do too much damage to collections, which was thankfully in museums, not my home.
My two cents.
Cheers and welcome!
Ron