Markov > Michalek, so I don't think that's the angle to work. The Habs do need to add a defender like Michalek... but to _complement_ defenders like Markov, not to replace him. But I think at this point the Habs are going to have to set their sets lower.
If any dman on Phoenix ends up being available it's most likely Klesla or Morris. A lot of that would depend on whether the team thinks Rundblad or Gormley could make the NHL roster this season. If neither do then they're set with 7 dmen and probably no interest in moving one.
If a player like Klesla or Morris were moved the desired return would probably be a roster forward of similar value.