A few thoughts:
In the past it was very common to "improve" a handgun with Pachs or Hogues, and just toss the original stocks! Since you have done some research you may not need this, but there is a great thread done by a Forum Member on N-Frame Stocks that may interest you:
Smith & Wesson N Frame Stocks / Grips - A Reference Guide
For your revolver, "1946 to 1967 Checkered Diamond Magnas" will be of particular interest. Be advised that one of the few options on an M28/Highway Patrolman was Magnas or Target Stocks. So the right target stocks would be appropriate as well, if that's your thing.
I'm glad you got a 6" version as well. My guess is that you will find it more pleasant to shoot with full power magnums.