I found pepakura a while ago and started to make a mark VI helmet out of paper which is now finished (check out my youtube for a how to video) and will (this helmet is test only btw) papier mache it and paint it a few times until I am good at it. Then make the helmet again using card, papier mache and paint. Then finally one from card, resin/fibreglass coat it and metallic paint it. If this goes well I will make the rest of the armour and make myself a suit (I am already making weapons too).
Oh yeah, I found this site on youtube after seeing 'dedicated to the 405th' by GameTavern!! That armour is L337!!