buck - actually, with all else being equal, there is no difference in accuracy between a 6" or 8" barrel. The 8" barrel may appear to be more accurate simply because of the longer sight plane allowing less human error to come into play.
If you are going to scope it, it really doesn't matter. I've hunted with both 6" and 8" revolvers and 14" single shot pistols (Contender).
One consideration is how far do you plan on shooting. Like a bow, you should limit your shots to your effective range. For me that was no more than 50 yds with 6", out to about 75 with open sighted 8", scoped 8" 100 yds, and the Contender easily 200 yds (with a good rest).