Teams like Philly and Boston will run them over... I'm not sure there is one player out there that makes them significantly better, or better to the point they are in the upper echelon of the league.
I think though, your proposed deals make some sense. Neil would definitely help. I think you might be a little light on what it will take to get Penner, but you're on the right track.
This is going to sound stupid, but I think this team has to be completely re-shaped. Move out whatever vetran contracts you can,( Gomez is IMO almost unmoveable, with his contract, I like Cammi & Gionta) They have drafted terrible over the past 25 years, and haven't really had a marquee guy since back in the early 90's.(Roy)
A guy like Rick Nash comes to mind. A big guy who can score, and is still young is what this team needs. It would take alot to aquire him, and he is the type who needs a supporting cast, but he would be a guy I would be targeting if I were the Habs..................