kind of irrelivant becasue skylines only need 3 outputs. they fire two pistons at a time in parralell so 2 fire, 2 squirt fuel at a time
i run the stinger on my rb20 and my mate runs it on his rb25det vvti (ems supports the vvti) with no hassles at all, both wired into the factory harness supporting factory sensors and idle controllers, cant go wrong for the price you pay... map sensord so i would compare it to an apexi d jetro, but with way more added features and options such as lauch control,rotational idle, antiag, nos the list goes on.. only catch is you can basicly only pick one as the car will use 3 outputs (tacho output, fuel pump relay, aac? valve) so that leaves you with one optional output
out off the list above,I HIGHLY recomend EMS dude especialy if your looking for the cheap alternative