Need Help! What amp do I need for my speakers?

[MCM0726]

I need help deciding on what power mixer to use for my speakers. I have 2 CGM speakers (250W at 8 ohms) and a CGM stage monitor speaker (250W at 8 ohms). I don't want to under- or overpower my speakers.

I was using a Behringer Europower PMX 2000 (250W at 4 ohms in stereo mode). However, it quit working on me one day. Someone told me the problem might be the transformer. I connect each main speaker into the amp and the monitor into a monitor input on the front of the amp.

I want to purchase either a Yamaha or Peavey power mixer, but I need to know what kind of power I need to be looking for. If anyone has any idea or can help me, please let me know. I appreciate any help.