not sure if it was posted up already, but what rotors were you using? i dont see anywhere it was mentioned other than they were machined with 100km on them. if they're not at least slotted upgrade asap.
if they're not slotted, buy a set of the r32 gts4 rotors, they're the same dimensions as the U13 import rotors but available off the shelf, no machining, no modification, no buying blank and having drilled to 4 stud. i was running dba kangaroo paw slotted in my setup. obviously i didnt end up racing in the pinny, but its worth a look if you're not running them. the skyline brakes the only upgrade is the extra 2 pistons, the rotors are the same size but need to be machined down to fit because of the mounting brackets for the calipers.
also you can indeed get dba green/yellow/red for the maxima, they're the J30 maxima yeh? problem is we live in australia and you know, commodore/falcon or you get no parts
you will most likely have to order from the usa. the parts are:
ebc green: DP2775
ebc high friction: DP4775R
ebc red: DP3775C
ebc ultimax: UD430
or if i was wrong and its the A32, then your part numbers are:
ebc green: DP21752
ebc high friction: DP41752R
ebc red: DP31752C
ebc ultimax: UD653
not saying use EBC over QFM, but the option is definitely there.
and i know off topic, but the U12 pintara front brakes are the same as the R31 skyline, your pad options are:
ebc green: DP2792
ebc high friction: DP4792R
ebc red: DP3792C
ebc ultimax: UD485