With regards to the powered/non-powered mixers and speakers, it's really simple. If you have a non-powered mixer, you need active speakers, and vice versa (powered mixer - passive speakers). Active speakers are generally more expensive than passive, so I'd go with a powered mixer and a pair of passive speakers. That being said, you might not get everything you need for under a grand. Clarify for me, you need:
A mixer
A pair of speakers
Monitors? How many?
You've got mics, so I'm assuming you have enough cables.
I use a Yamaha EMX660 powered mixer, which has been discontinued, but I've had it for 8 years and it still cranks. Comparable model:
http://www.musiciansfriend.com/product/ ... sku=630190
Or lesser wattage (2x200W as opposed to 2x300W as posted above):
http://www.musiciansfriend.com/product/ ... sku=630192
A little cheaper, but you're also getting less power.
Speakers, on the other hand, are very broad, you'll have to go to a store and listen to something being played through them. I use a pair of these:
http://www.musiciansfriend.com/product/ ... sku=601208
They've got a 2" compression driver in them to give the highs a bit more clarity, as opposed to a 1" on the comparable JBLs which I originally looked at. You could also look at:
http://www.musiciansfriend.com/product/ ... sku=601201
Smaller, less expensive, but again, they can't handle as much wattage, although with a mixer with dual 300W power amps in it, they should be fine. Anyways, it's all preference. I highly recommend the Yamaha mixers, but there are others out there that I'm sure work just as well, I'm just biased because the one I've had for years is still kickin' strong. Speakers are a lot trickier, and I'm sure someone else can help out a little more in that department. As for monitors, I use this old floor wedge running out of a drum-monitor subwoofer, it's a fairly ghetto rig, but it works, although it doesn't really help you that much. Anyways, good luck.