I believe Trijicon sells night sights for S&W "J "frame revolvers... if they have the wide version of the "J" frame front sight. I don't see it on their website either, but a couple of years ago I was looking for the same thing and I may have gotten the info from Trijicon by talking to them on the phone.
I suggest you call Trijicon, Mepro and S&W. I'm almost certain one of them make a night sight for some of the "J" frame revolvers.
Rich