What do you think????

I'm getting a apex N1 cat back system, a HI-FLOW converter, AEM v2 intake, and a DC 4-2-1 headers and I'm wondering if I should get also an ECU for my GSR but I read an article that getting an ECU w/o a MOD in your CAM shafts is useless since an ECU and changing your CAM shafts goes HAND IN HAND.... IS THIS TRUE??? and INPUT would be much appreciated... Thanx in ADVANCE