Meprolights for the SR9 have been out for a while now, but no one has seemed to get any, not even a product picture of them installed. A couple guys have ordered them, but nothing doing for any reports of them since being told another 6 week delay (IIRC).
I'd go for the Novaks from shopruger.com. Ruger's good about getting parts out and if your curious about delivery, give them a call.
Josh