I'm looking for something that looks good on lurking, stealth character. Preferably open faced, but not required.

Two things:
1) Yes, I've found the green gas mask hood.
2) I've checked the clothing shop in Diamond City. They didn't have any, but I'm assuming their inventory rotates on some schedule.

I'd be interested in any other headgear that fits the RP of a stealth character.

The guide lists 2 hoods I haven't seen yet.. Green hood (not the gas mask hood) and Bos Hood... however, it also calls that sack mask that raiders where a Sack Hood.. so who knows if those other two are actual hoods or not.

Hopefully there's something. It'd be a damn shame if there wasn't any.