If you're going to be listening to mostly hip hop (that's like rap but with more of a dance beat, right?), I would look at the set up with the M50s. You lose the QS8s, but gain more bass out of your mains - which I'm guessing you might prefer. I must say, however, that I have never heard the M22s, M50s, or the QS4s, and I know nothing about hip hop.
So, why am I writing this? BLTB.