possible material for large cfls reflectors??

So I've been doing non-stop research + store browsing and can't seem to be able to find any material worth making a reflector out of for my two 125w cfls(combined with the 150 HPS). I've got reflective wallpaper which i'll simply attach on. If anyone's got any DIY reflectors for cfls, i'd love to see them. Thanks for the help everyone!

FYI I place my cfls horizontally

home depot...look for some 6' duct