Best you're probably going to get on the forum, is a Jack cosplay; a search should find you the couple that have been done, they're all really nice. I've seen a few people do that, and one or two other off brand pilots gets started. I haven't seen any templates get thrown around, but it may be worth checking the "free paper templates/props" sub forum.
Gonna try and hunt down some files for you now, but I also gave Etsy a look for giggles. I did not find Grapple. I found Pulse and Phase-Shift helmets. I can't remember the name of the other style of helmet, but I found that as well.
Hey guys I know I'm probably a few years too late but I've actually managed to make a grapple helmet out of foam using my own templates. I still need to add the respiratory barrel things at the bottom, but I will eventually get around to digitising the templates I made if you guys want to make one yourself