Help needed for Camera in helmet

Hey everybody i'm doing a warframe cosplay

( can be watched here : http://www.therpf.com/f24/warframe-cosplay-182806/ )

And i'm looking for help because i want to put a camera and a screen in the helmet.

I know some people are doing it when the helmet can't be cut to add eyes or hole to see.

So i hope my english is right and you will anderstand what i'm looking for.

All informations about the systeme are welcome

price
where can i find it (in france xD)
what kind of battery did i need to make it work ( 12v 9v battery ? )


Thx you very much for futur help :)

Nico