Just to keep this in mind, the wigheads that are used to show the wigs on cosworx are a little small, I've found that the average person's head (who knows, maybe I just know people with huge heads) is a bit bigger than those so the wig isn't as long as it might look. I've found that its a good idea to get a wig longer than you need and trim it to the length it needs to be.
I noticed before you seemed to have a problem with razors. You can use eyebrow trimmers or even bikini line razors, they're not open edged flat razors like you might be thinking of, they've got plastic handles and they're pretty hard to cut yourself with. If you're still uncomfortable with them then you can try thinning shears (seen here
) they don't give quite the same effect as razoring your hair does, but it'll keep you from getting straight cuts, which look pretty terrible, and it'll also give the wispy sort of look that Ritsuka has.