To be honest, none of these areas are in my zone, but I know about all a little bit aside from taxes and housing for the most part.
Of those 3, if I had to choose, it would be Conyers. About 13 years ago, i lived in Lithonia which is sort of in the middle of these 3 areas.
Joneboro, Crime would be the highest, no wiggle room, nuff said. Commute would be the best but not by too much over Conyers. Just don't pick here because it is not good. Schools/and everything. Sorry so short, but do not pick it!
Conyers, I have know several people that live out there and it has really picked up with housing and everything. Good schools and not far from downtown (30 min, i guess). definately suburbs. I wrestled against Newton county high school )Conyers) many years ago, and it was an awesome new school. LOL, still does not mean it is good, but I think it was and is now.
Stockbridge, I know the least about, but i know it is farther down I-75 and Henry county has picked up in crime like the city. (always on the news there are drugs and robberies) definately burbs, but not goos overall.
Go for Conyers! or check northern ATL burbs, everything you want, with small compromises.