They are essentially selling an adapter to bolt the rbc manifold on the 2012. The link I posted earlier explains the holes that need plugged etc. So, you either modify the manifold yourself/have a shop modify it, or you pay for the adapter you've posted. The peanut shaped hole isn't modified on their manifold. Their rubber o-ring adapter supposedly would stop the leaks, and save you from having the manifold machined.
What's the turn around time for shipping? How does it fit if I have an aftermarket short ram?
the rbc unfortunately moves the throttle body to a completely different location. getting your short ram to fit may be possible, but it also depends how creative you are and possibly how good at fabricating. the best solution is an intake that fits the 06-11 SI