Very helpful. I was able to find a few sites that explain how to vacuum form plastic in your kitchen, doesn't seem too hard, it's relatively cheap, the most difficult part will be making a base for the pieces.
Vacuumforming Plastic
I too am looking for ways to make a space costume to coincide with the release of Prometheus. Looking at some other pictures, I got the idea of using my morphsuit as the skin of the suit and somehow crafting the other body parts from plastic.