They look like basically the same setup aside from the different calipers (which if I'm not mistaken are the same volume anyway) and the slightly thicker discs..
This article (if you haven't already seen it) might give you some good ideas. Of particular note is the fact that you may not need to machine the discs (in your second option) down quite as far if you're going to be running 15" or larger wheels..
Your second option is basically what I PLAN on doing when I finally get around to it, although I'd be wanting to try and keep the discs as large a diameter as possible.