Am I choosing the right coilovers, and what supporting mods do I need?

MaysEffect

Dampers are not your main concern, all of these kits will give you a good damper. Your main concern is spring rates. If you only want to do this one time, then you need to sit down with a tuning shop and have all your measurements plotted out before you just toss on any kit. If you don't have a reputable/skilled suspension guru in your province then you'll need to do this your self.

First you'll want to find a way to measure how low you want to be and the potential wheel clearance with whatever wheel/tire you choose. So it's actually best to get whatever wheels you want and then lower accordingly. A taller tire is worse than slightly wider. If you increase width a lot, you may want to consider reducing diameter a small amount. You don't want to go smaller than 26" overall. This is an art within itself, but luckily the z has gigantic wheel arches.

Your new spring rate should be based off of your common daily weight (car+you+fuel+fat bitch passenger+luggage) relative to the NEW static ride height and total permitted wheel clearance at full lock.

Technically you can definitely achieve your target ride height without getting a pre-made coilover kit, but using an off the shelf "spring kit" will most likely be the worst option over time. It does however save you money which can go towards wheel/tires and other suspension parts as advised above. You'll definitely want a camber correction kit at minimum which cost just as much as coilovers all said and done. The lower you go, the worse your camber will be, necessitating a camber kit for proper alignment.


Rant over ✌️