What is the purpose for the revolver? all the questions you are asking will be answered by the purpose.
EDC- lightweight 1 7/8" bbl -637/638
Holster carry- Stainless Steel- 2-3" bbl- 60/649
I don't really see adjustable sights as practical on a J-Frames. They are meant to be fired fast and close.
If you are looking for a range gun, go up a notch to a 686 in 4-6" bbl.
If you are looking for a gun that is going to be both, you are going to be falling seriously short in one area or the other-CCW or Range. I have J-Frames and two 686. The J-frames (I EDC with a CCW) are slick (fixed sights and no lasers) and easily concealed.
The 686 are both dreams to shoot on the range.
I don't shoot at 25 yards with the J-Frames and I don't stick a 686 in my pocket.
Somebody is going to jump in now with how they can hit shotgun shells on a regular basis at 25 yards with a J Frame 3".
It isn't that I doubt them, but I wouldn't buy anything from them!