Get a ballistic helmet, if you cant afford or find one, get a motorcycle helmet or even a construction hardhat. The airsoft larp gear will just get you hurt.
Also, and this goes for ballistic plates too, if it ain't NIJ certified it is worthless and will get you killed or injured.
https://www.hardheadveterans.com/blogs/reviews/bulletproof-helmets-what-you-need-to-know
Where can a get a good helmet for a reasonable price? I don't have $1000
You can pick up a FAST high cut helmet used around 300, and guaranteed to work with any gas mask or respirator you might need. My second choice would either be a construction helmet, just so I could still use gas mask/respirator or a dot rated motorcycle helmet, which you could still use a half mask respirator with unless it's a full face helmet. ( In which case make sure you have good eye protection.)
Everythings out of stock because panic panic panic, but you used to be able to get surplus ACH helmets for like 100-200$.