While this is a really good feature of the game the options are too limited, there are only a few hats that can get this upgrade and they are the ugliest hats in the game. (news cap, battered Fedora, and maybe one other)

Hats that would be good options for this upgrade:

Military Cap

Assault Gas Mask

Minutemen general's hat

Minuteman hat

Militia hat

Maccready's hat

Lieutenant's hat

BOS Hood

etc...

Outfit that should have the options as well.

BOS uniforms

BOS Officer Uniform

Colonial duster

Synth uniforms