I guess that precludes using a T3 - for the confident performer, it's unlikely that the audience would notice the difference between that and a Casio (we have all heard amazing demos from talented - no doubt confident - performers using these), or, come to think of it, a Bose sound system...

If you are confident enough, a pair of 802's would satisfy your audience, if in a small enough room.

It's interesting to hear you denigrate the use of a stereo Bose PA, without for one minute considering the absurdity, by your own argument, of the need for a mono one either...

Confidence, if applied according to your rules, would negate even the need for that. So, what is your insecurity? Do you think your karaoke tracks sound better on the Bose? A confident singer wouldn't worry about that...