They are available already on a limited basis through ARMS (they are the ones who make this system in case you didnt already know). I think you can place an order directly from their www site located at www.armsmounts.com
. For discount pricing, contact www.sableco.net
. The SIR probably wont be on their www site, but email them and they will give you the info you are looking for. I am looking towards getting one of these myslef!