Performance fabrics are nice... but you'll want more options:
http://www.clicket.com/costume/hero/hero.html
http://www.clicket.com/costume/hallo...es/batman.html
FYI- my birthday is this wednesday, hurry up and get the women's small for some pre-race extra credit:
http://www.costumecraze.com/superdlx-superheroes.html