You got that backwardsI wouldnt say extreme sound quality... They are much more SPL oriented than the W7... But all in all, yes the W6 will produce more SQ and the SA-12 will take more power.
Yes IF the build is set up for it.. If all you hear is rattles then you will not take advantage of the W6 SQ. It will just be a good looking not loud subis there a big diference on sound quality between these 2?