Well, I'm no expert hairstylist... but I don't think the hair should be to much trouble. Just fluff out the wig, take some of the hair, and tie it in a ponytail. Don't worry if it isn't perfect -- a lot of anime hairstyles are impossible in the real world. Just use a special hairspray for wigs and you're good to go. Not sure about the hair piece...
As for the sword... well it's possible to make one from cardboard with Paper Mache or Plaster of Paris.
Paper Mache is easy -- you just need strips of newsprint or newspaper and a base for the sword made of cardboard (which shouldn't be too difficult), as well a special paste made of the following ingredients:
1 cup water
1/4 cup flour
5 cups lightly boiling water
Just mix the flour into water until mixture is thin and runny, stir into boiling water. Gently boil and stir for 3 minutes. Make sure paste is cool before using it.
Plaster of Paris can be easily found at any craft store, although you could make the Paper Mache paste for
free 
You can then paint the "sword" with acrylic paints and decorate with jewels
I hope this helps
