Most cosplay wigs are meant to act as regular hair..so...yes.
I'd say pigtails.
buychina Amazon
Try ebay.com, they have a large variety of high quality cosplay wigs.
Hello Cosplay
Hello Cosplay or Amazon
This is all I can find: http://www.cosplaymagic.com/nashabcowig.html
Try looking up different cosplay sites and ebay.
Well, obviously. Unless your hair actually looks like hers..
Suggestions:EbayAnime cosplay sitesYour local anime storeYou can make it yourselfOr find a store online.
Are you going to a anime convention? You don't need to cosplay. It's not a must... unless there is a rule for that particular convention.You could just wear a wig and a cute outfit, and say that the character you cosplay would wear this too. Or just wear something similar. You don't have to look exactly like that character.
Look for wigs on Ebay. Or take a wig from a wig store that is the same color and style it yourself. www.wonderlandwigs.co.uk also do some good quality anime and cosplay wigs. Or standard wigs in a rang of colours which you can then style.
Messy, messy, messy! Black hairspray/dye for the color, and then ruffle the wig with gel.You can see some neat examples if you look up images of 'L Cosplay'.Hope this helps! ^^