1) From a practical, economic stand point, if you are installing height adjustable coilovers, you need an alignment. If you install adjustable arms, you need an alignment. Why would you want to pay for two alignments? Even to save a couple hundred bucks or whatever, collect all parts and install once. Set the height you want, then set the alignment specs, and be done
2) Let's be clear by what you are referring to: true type coilovers are coilovers in which the spring is wrapped around the damper; as opposed to OEM or "divorced" type. Not every coilover MFG has both types, be aware of what you are buying
3) True vs OEM type has multiple effects. First, spring rate. True type coilovers put the spring further inboard and therefore require a lower spring rate than an OEM positioned spring. the relationship is ROUGHLY 50%, someone smarter than us did the math and testing. If you wanted 10k OEM type , you would get 5k for a true type. Make sure your retailer and coilover manufacturer is aware. Further reading is available, if u want
4) true vs OEM affects which toe arm you want. True type coilovers eliminate the "bucket" that the OEM spring sits in, so you would get just the "toe arm" (like this:
https://www.splparts.com/products/37...mid-links.html)
If you get OEM type you want a "mid link" like this:
https://www.splparts.com/products/37...mid-links.html)
Either way, you will want to get the traction and camber arms at the same time/same install. Full adjustment, one installation, one alignment.
5) When you say you are getting "all the nismo arms" which arms are you referring to?
The silver with red trim arms branded as "Nismo" are simply recolored/rebadged SPL arms with a 10% or whatever price bump for the name. They look hot as ****, if u can afford, i salute you. Otherwise, the equivalent SPL part will save you a few bucks as its the exact same part in black/blue. C
6) You didn't mention the fronts - YOU WANT THE SPL/NISMO FRONT UPPER CONTROL ARM (FUCA). There is no adjustment for camber/caster for the Z in stock form. With no adjustment you are stuck with whatever random setting you end up with after you lower the car. This will f-k your tires and driveability
More importantly, camber and caster are critical to proper wheel fitment. If you have these arms you can be awesome and run an 11 inch wide, +15 offset wheel IN FRONT. If you have no SPL arts, you are lame and have to run a measley 9.5 +22.
READ THIS:
Wheel Fitment 101: START HERE
Don't be lame. Be awesome. Get the SPL/NISMO FUCA
Additional notes:
Don't know which coilovers you're shopping, but look at Fortune Auto, run by prominent members here. Stateside support, ships from . . . Virginia, i think. You can order custom spring/damper settings. True and OEM type available. Rebuildable stateside. They have an air-cup system, although that may be out of stock due to parts shortages, check with your retailer.
Cost should be under $2000, which is reasonable depending on how much stuff u add. Also, springs upgradeable to Swifts
Track and street proven
Powertrix is also good, made by a Z guy, for similar prices. Based in Socal i believe.