Not 100% sure, but I think the helmet base is a US Navy BPH-1. Replace the ear cups with the new style, and vac form in place.
Does anyone know if they had this costume on display at Celebration? Good pics from Celebration would go a long way for making out additional details as well as information on the materials used.
Offhand, I think that whatever material was used for the base flightsuit is pretty heavy judging by the way it drapes and I'm think that this would be a hot costume to wear. My guess is that the suit is made from Nomex but that would be unnecessarily costly, a heavy cotton duck might be more likely.
I can almost say with certainty that it was NOT on display. I have been on a lot of Star Wars related site this weekend and seen plenty of photos of Star Wars:TFA props and costumes on display and i have not seen anything Poe or Resistance Pilot displayed.