For the armor parts I'd suggest craft foam, paper mache, cardboard, sculpey, fiberglass or wonderflex. Also, try alot of metallic paints and use stuff like polyeurthane, gesso or Mod Podge to seal it and make it shiny. Or better yet, a combination of whatever you can use out of this stuff or whatever else you may use.
The outfit itself...Maybe a heavily modified bathing suit pattern, or even a corset. I would use stretchy fabrics like stretch velvet, bathing suit knits, latex, PVC.
The wig, I would choose...http://cosworx.com/product.php?produ...at=2447&page=1
I would definitely style it some/ trim it and get it in 60 (white)
This will be pretty difficult I suspect, especially for your first costume. Good luck though.