Check out your local used music shop Atomic Music on Rte. 1 in college Park. I would recommend Crown, Crest, or QSC as being highly respected and reliable manufacturers. Look at about 500 watts per channel to not clip the peaks (better to have too many watts for the speakers than visa versa).
**edited as an idiot I had put QCS not QSC**
**again go to atomic, they have the stuff cheap**