The way I see it, if the cobalt one is that important to you, then wait for it. Downside is it might never be released in NA. If you can survive with a different color, you could always get the light blue one or something more basic like the black one, and if it comes down to it, replace the housing with a blue one when they become more readily available to purchase.
But you also gotta factor in how much you want the system itself. If you're on the fence, then I'd hold off, and see if maybe the cobalt one will be released at some point. But if you want it really bad, then the above applies.