Neato! I'm diggin the refined concept - definitely a clearer direction. I'd recommend mixing the shoulders together, having a different variation for each shoulder. Right now, one of your design's weakness is rigid symmetry (currently) so to counteract that a bit, I'd throw in some mismatched shoulder designs to inject a little asymmetrical interest in there. This would also double as a means of picking two of your favorites instead of just the one for both side.
As for the weapon, I'm actually liking #4 as well, but #8 might be neat if you gave it the handle off of #5.