Oli, You will be fine with z-coils and bils shocks if you don't tow a lot or really heavy stuff. I use the bags cause I tow a 14' 5000lb box trailer with my pressure washing and recovery rig in it and it stiffens the rear end when not towing. Even if you don't tow I think there worth the money for the improved ride but you don't really need them. Jason is right on the money about payload and nivomats. If you don't get the coil springs you'll have a sloppy hoe, lol, even if you put the bils on!