How much are you looking to spend and what are the features you want?
I'd like to spend about a dollar a watt, since this isn't a high fidelity application.
But I'll go higher for the right hardware.
I need 70v output, 100w (I could probably get by with 90w), a dynamic microphone input, ideally a line input (for CD or tuner), and a volume control. That's all I need - this is for yelling at children who might be anywhere inside or outside an acoustically voice-eating home. I'd like THD to be below 2% near max output, but it's negotiable. Often the unit will only be driving 30w of speakers at a time, but sometimes a total of 90w. It will carry voice in almost all cases, so I don't really need a wide frequency response. 60Hz-15kHz is plenty.
For extra credit, the speaker would have 5 or more speaker-select buttons, and the frequency range would be wide enough to permit playing soft classical music without sounding terrible. (70v systems are transformer systems, so I don't expect reproduction below 100Hz to sound right in any case, especialy since most of the speakers are 5".)
The unit has to be reliable, though. For extra extra credit, being runnable off a 12v car battery would be nice.
For super extra credit, it would have three buttons, which play pre-recorded .wav files:
"Get down here. It's late."
"I said get down here NOW, or it's going to get very unpleasant around here."
"That's it, you're grounded. Now we're playing for how many days you're grounded. A day a minute..... at the sound of the tone, your life will be miserable for two days.... at the sound of the tone, your life will be utter hell for three days...."
You'd think this would be a booming market, actually.
