Get DiMarzio DP126. Its a Model P + a Model J. My personal opinion is that the SD QP's lack that little something extra and sound kinda dead and lifeless to me compared to the DiMarzio's. I know a lot of people love the QP and I get it, they just don't have the voice and personality of the DiM's.
A matching set is always a safe bet but I would not be too concerned about some mix and match as long as they are both hum canceling which, P's are naturally hum canceling so its not a big of a concern finding them. its the J that you have to find specifically like that.
Honestly if you really like the QP then get a matching one.
Ibanez Club 1137 - Da Chunky Funk Club 15