The suit and helmet were both made by Ithica. The helmet is indeed a Halo 3 EVA helmet, and the armor is EVA Foam, using heavily modded N7 armor templates from Mass Effect. I built the railgun that the spaceman wields. I'm kinda disappointed that they didn't use the pepperbox grenade launcher, or the "Eviscerator."
Here's a bigfoot style fuzzy photographic evidence of our works: