Your powered PA speaker system should suit your needs. The first choice would be sound quality. Make sure that the system works whether you will be using it for music or speaking. The next consideration would be size. You should be able to transport your system wherever you are going, but, at the same time, you want to get as much sound as you can.

You will not need a separate amplifier or mixer. Depending on which model that you buy, you can also get a built in
microphone. So, if convenience is important to you or you have limited space, consider a powered system.

You can find powered PA speakers from the top speaker makers. Yamaha Pro Audio has a full line of PA systems that will fit your budget. JBL Speakers has everything from 12 inch ultralight which deliver top sound without taking up a lot of room to the value driven EON 315 which is also lightweight. Peavey makes a more affordable line of speakers as does M-Audio.