If you want to carry a .357 mag, I would consider a K frame S&W revolver....... to handle the recoil. A J frame is suitable for .38+P, but I think that .357 can be a handful. A 19/66 or similar revolver is slightly bigger and heavier, and can easily handle .357.

I have a M-66 2 1/2" , and it's in a quality holster. (Bianchi Shadow Pancake) It doesn't seem to be heavy or too large, at all. A quality gun belt helps, too! It's much easier to shoot .357 Mag in it. You will have better control over the revolver, too. The J frames can be harder to shoot accurately. (It's important...... when you use a gun in an emergency situation. ) Bob