Since we already have joint textures released, perhaps some other form of neon?
"Toys" (bands, outlines, etc.) would be cool to have, would just need mapping and coordinating with the axis' when they're put on.
Outlines are what I were saying. Custom outlines at that. Textured neon can cost 3 USD or 10k. Same color as force/relax can be used like every other item. I'm not saying I want it to be flat, but it should be camera-following. So It won't appear flat on the ends.