I have buy a QSC GX7 in 8ohm is725 watt and in 4ohm is 1000w my speakers is 500rms, 1000 program peak 2000w peavey i want to know if i can use the QSC power amps with these speakers or change these speaker into 4ohm to get the 1000 watt or the will be fine with the 8ohm in 725w
Since even into 8 ohms your amp has more power than the speakers can handle you are fine.
Be careful because you could blow them.
If you get 4 ohm speakers make sure they can handle 1000w. You have to go by the RMS ratings since peak power is not usually accurate.