Congrats on starting your first suit. For high durability, fiberglass is usually best, but does require a good deal of work. As mentioned, foam is also an option. Both of my halo suits are foam, with a fiberglass helmet, solely due to durability, and that the helmet walls are thinner when using composites, whereas, EVA tends to be rather large. I would look on the 405th.com. under the file archive option, they have a large collection of pepakura models. simply download pepakura designer, the model you choose, and print. paint it thinly with fiberglass resin, and then on the inside reinforce with fiberglass matting. I find stippling this on in a manner similar paper mache'. I have also found that using mogepoge to reinforce helmets can work, albeit far less durable. the advantage of this iss that there are no toxic fumes to deal with, so it may be more accessible for you. Alternatively, instead of pepakura, you could free-sculpt a helmet over a hat form head, out of clay. once this is finished, coat it in roughly 8 tubes of silicone caulk, and make a paper mache' coating over this. once cut open, you can reproduce the helmet by pouring in, and slush casting a resin, bondo mixture. both methoods should then be filled and sanded with body filler, generally bondo. This is how I produced the helmet in my picture on the left. regardless of which method you choose, I would recommend something like the Skull of Dire Ahamkara, as it's organic shape is easy for a first time bondo-er.
