I would say depending on the area.Near me memphis does not seem to sell used very well.I would do a 15" mojo with 2000 watts rms //content.invisioncic.com/y282845/emoticons/bowdown.gif.b85b23b82970bd22fb6b549c3392f016.gif
I would go with the singe MOJO 15, you'd be more than happy with it. I had one setup in my old boss's ride with 900 watts and was very impressed with it, even with the low power.