craftgrrl | question - fake dreads

Hi! I was wondering if anyone knows of tutorial sites/has their own suggestions on how to make realistic-looking dread wigs? I dont mean those cyber-goth ones that are usually spun wool, but something that looks like actual hair, like this. Would it be a good idea to buy a halloween wig and actually dread it up / would it look like that, or is there soem other product I need to buy? The one there looks more spiral/coiled than dreaded, and i wouldnt know hwo to go about doing that on wig hair, either?