If you are going to use this as a hunting rig then I would opt for the longer barrel. You aren't going to be making lightning quick shots from the hip out of the holster so the shorter barrel will not be a real advantage.

The longer barrel will provide you with more velocity, a slightly stadier aim with the added weight and longer barrel, if you aren't going to scope this gun then the longer sight radius should prove to be more accurate, 4.5 ounces will never be noticed in the holster and that weight can be made back up with a light weight holster.