I need a microphone (PZM?) that I can use for a stage play that will boost the sound of the actors.?

PZM microphones really aren't very good for ambient sound applications. They are best used when mounted on hard surfaces. It's true that it will work, but not all that well.

Your best bet is to use overhead microphones. I would recommend at least two or more depending on the size of your stage.

Sure makes a pretty good one.

http://www.google.com/products/catalog?hl=en&q=ove...

But if you are looking for something more affordable, you can go with NADY.

http://www.buy.com/prod/nady-ohcm-200-overhead-han...

There are many more out there, so you may want to do some Google searching for "overhead microphone". And remember, most of them will be condenser microphones, so they will need phantom power.

PZM's do not work well for the stage. Most theater's use wireless headset type mics now for each actor. As the other person said, if you can't afford wireless mics, just use condensor hanging type mics:

http://www.amazon.com/Audio-Technica-Pro-Hanging-C...