If you go to printables website they have the helmet and on thingiverse website they have a few other piece parts.

Just a heads up. Depending on what filament you use it will not be cheap or fast but best of luck. Project should be a ton of fun.

Would be also a lot of fun to make the models from scratch. Fusion 360 (CAD) hobby or Blender 3d (art focused 3d modeling) are free to use.