I was thinking about getting a normal Black Rock Shooter wig and having someone cut one clip shorter and adding some layers to help spike them. I don't know what to do from there, what products to use,etc... Someone please help me.
vensy has a guide on how she did her BRS wig (which is awesome) http://www.vensy.net/blogging/brsb-styling-the-wig/
if you haven't done any type of wig styling before, I wouldn't recommend this because it's got a lot of advanced techniques like foam core and such
My technique with styling giant spikes in wigs is 'the hidden wire'. Like it says your putting wires inside the wig to help support it saying up. I don't think it'll work on your BRS because you would require a metal base for the wires as the hair is SOOOO long. But you can give it a go.