We have used several Kuston KPA-100's for rock n roll summer camp rental. They are almost perfectly suited for this.
Unfortunately, the price went up over $100 in the last year. Should not have happened, and it moved the PA from a great value to only okay.
This little PA sounds quite good for what it is. Use this for vocals, only- you won't get chest-thumping bass from 10" PA speakers, but in a rehearsal, the bass should not be going through the PA, anyway, and use a keyboard amp for the keys. 4 input channels are usually more than enough for most bands. You could even use it for the PA for a house party, but don't bring it to a mall, club or outside performance- it just does not have the power to be heard there.
Eventually, this or any other entry-level PA will let you down- either because it does not have the power you need for larger spaces, or because it breaks down. If it breaks down, toss the mixer/amp unit, get a bigger PA, and hack off the back edge of the speakers, making them into floor wedge monitors!