Federov is a half decent face off man, and would definitly help out the second line scoring.
Anyways, go Cristobal Huet, who once again showed why he should be the Vezina winner.
Fedorov would be a nice second line center that can help with Ryder and Kovi a lot, but that means probably giving up a talent like Ryder or even Markov with a few draft picks because of the salary.
So I'm going to a bit biased on my ultimate lines, because there are so many great Habs players.
First line:
Boom Boom-Gretzky-Richard
Lafleur-Beliveau-Cournoyer
Gainey-H. Richard-Dionne
Mahovolich-Messier-Espositio.