1500+rms vs 2200rms... the AQ takes it power wise, but quality wise I can stand behind the SAZ1500 100%, it is welll worth its price (especially used). just as strong at 1/2ohm as 1 or 2 ohm. I havent had any experience with the AQ amps, but they are priced very well.
This time I would vote for the AQ, but only because you are running subs that can take a full 2,000+rms. If you only need 1,500w, i would definetely vote for Sundown.