Brian hit the nail on the head. I don't want to see your scratchbuilt helmet hit the ground and burst to flames, I'd feel safer and more comfortable with Rubies than scratchbuilt.
I wear a scratchbuilt Jet Pack and I hate looking at the thing, if I molded it then I'd be happy with it. The jet pack is something different though, it's a solid case, filled with expanded foam, and it's mounted on my back; not something that covers my head and is not an "often screwed with" item, besides the thrusters.