Both B12 and B13 came with same E series engine in Pakistan.
In the case of my B13 with QG15, very little adjustment was made on gear side mount. Rest, every thing fitted bolt on. I guess, same should go for B12.
Regarding GA16, it will be very rare. And even if you find one, it will probably be already end of life, being discontinued long ago.
QGs are JDMs, new generation and available in higher numbers. Which means, finding parts will also be easy.
Rest, choice is yours...