Thanks for the idea on the backpack Cag. I might end up making a mold of clay, and injecting expanding foam into it, and then layering thin sheets of metal over it. Currently awaiting my step-dads free time next Saturday so I can sit him down and get his opinion (machinist of 20 years, and my partner in my armor business.).
My main problem now is the skull... How should I do this and make it look like bone, or whatever a Chaplain would have on his helm. This mini below has been brought to my attention as a possible lead, and I might even try to make a jump pack for the armor, as this might be easier to craft.
http://gamesday.us.games-workshop.co...gold_large.jpg
Or, possibly like this (but not termie armor).
http://gamesday.us.games-workshop.co...onze_large.jpg
Thanks for the ideas and encouragement. More to come as I talk to the others i'm wrangling into this project and get specifics nailed down.