Except for the sights and the magazine extension, is the Mossberg 930 Home Security (85320) the same as the SPX (85360). I was showing a picture of the SPX to a friend who said he had a Mossberg 930. When I looked at it, it look exactly the same as the SPX except it had a beaded front sight and no 2 shot shell extension. He and his wife our expecting their first baby and do not want the gun in the house. He said it only had one box of shells through it and would sell it to me for $250.00. If the SPX is a stronger gun I would rather spend a few more dollars, if they are the same maybe for a few dollars I just need to add the 2 shot extension and sights. What do you suggest?