I disagree with your thoughts on being a man-to-man team when you have a shot blocker. To me, teams with good shot blockers are better situated, and the shot blocking player is better featured, when playing zone.

In a zone the perimeter defenders are able to play aggressively on the wings, going for steals and disrupting the offense’s flow by starting the offense further away than what they are used to. This can be done due to the fact that there is a good shot blocker who is babysitting the basket. In a zone the defense knows that the shot blocker will be in the area of the middle of the paint at all times. This way if the perimeter defenders get beat they can at least “funnel” the offensive player to the shot blocker, who will in turn alter or discourage a good shot. If a team with a good shot blocker is playing man, the offensive player who is being guarded by the shot blocker can pull him away from the basket simply by floating out to the wing or high post. This situation can be further exploited by inserting a good jump shooting big man or going with a quicker line up if the team is going man to man.
I feel it is much easier for the shot blocker themselves if the team is playing zone because he doesn’t always have to run and give help to the man who just got beat and leave his man responsibility.
I do not think man to man is the obvious choice. A simple 2-3 zone would work fine for a team with a good shot blocker. Personally I would be playing a match up zone if I had a good shot blocker and was coaching in High School. The responsibilities are easy to teach and learn at that level and the defensive look it gives can confuse the offense at times. Playing the match up zone aggressively could lead to an offensive player choosing the dribble drive into a tight spot with the shot blocker waiting to reject his shot opportunity or at least create a turnover situation.