And after further reading...
It sounds like you're going to have to haul your own PA gear around, which is a complete and total drag. I did that for a long time and I'll never do it again, unless the Queen is in attendance or something.
But if you gotta.... Buy powered amps. Avoid an external PA at all costs as they weigh a ton, and need their own enclosure to be moved and hauled about. Buy a mixer with a separate control room buss that you can use to send to your monitors without tinkering with the mix going to the crowd. Buy four of em. Two for the crowd, and two for stage monitors. If you can get a wireless headset monitoring system, that is a way better option than floor monitors. They can be expensive, though.
I have a couple of Pyle 600W powered speakers that I plug into a Behringer 2442 and it works great.
Ultimately, though, the way we fixed that was simply not playing places that didn't have their own sound system.
Someday we'll win this thing...