absorber

Hello guys, I have a pair of front 1.5" strut spacers installed and a pair of 1.5" rear spring spacers installed. However because of this set up, the rear shock absorber got stretched longer by 1.5" and as a result, it has a much shorter downward travel and a longer upward travel. The problem...

So there's an excellent guide on here for how to replace the rear shock absorbers on the Mazda5, but I'm torn as to which parts to get as my driver-side rear appears to have blown. With fear of it failing the imminent MOT, I better get on with replacing them, so any pointers would be most...