[Lonman]

What is the model number of the speaker for reference? Speakers will usually have 3 ratings, a RMS (continuous)/Program/Peak rating. 250 watts could mean one of those three, if it is the continuous rating you'd want an amp that puts out around 500 watts per channel into 8 ohms. If it's the program rating you'd want an amp that puts out 250 watts per channel into 8 ohms. If it's the PEAK rating, you'd want an amp that pushes 125 watts into 8 ohms. Rule of thumb to properly match your speakers is to get an amp that pushes at least twice the continuous rated power - 'program rating' (which the program power rating will generally tend to be double the continuous & the peak rating will be double the program) for maximum efficiency & headroom.
Looking at some CGM speakers it LOOKS as if the speakers program rating is 250-280 watts at 8 ohms, so get an amp that pushes this power per channel. But not knowing the exact model, can't be sure.
Sorry Doug, biggest mistake people make is to see a speaker rated at 250 watts continuous & get an amp that pushes that amount. What happens is the speaker can take much more. Say you are in a club & pushing the volume to a nice loud signal, well more people come in & the absorsion factor kicks in & now you need to kick the volume up higher, well the amp was already pushing at it's maximum clean signal of 250 watts, anything over that signal will now hit the speakers as distortion (clipping). You may not even really detect it audibly, but the speakers can feel it. This is the leading cause of speaker failure. You can blow a 100 watt speaker with a 10 watt amp, underpowering is bad!!! But on the same note, you wouldn't want to get an amp that pushes much more over the program rating of the speaker either.