What I meant by adjustment is do you have a need for uhh... lets call it "race car" level adjustments, or are you just trying to be able to drive the thing while it's lowered?
Those will draw a line in the sand before you start going with adjustable lower control arms and insane upper camber plates and such. If you aren't doing HDPE's all day with slicks... those aren't "necessary" and may in fact not even be nice!
Things you need to consider.
1. Springs.
Springs should be looked at as a RATE. Height is secondary. The reason the ant nest gets kicked over with the IPD springs is because they won't give anyone a spring rate. As such... for many suspension snobs, they'll get categorized merely as "lowering springs". If budget is no option, I would HIGHLY recommend going with coilovers. You will of course STILL need to select a spring rate, and pair it properly with...
2. Dampers.
Need to be paired with your springs in both travel, and rate.
3. Reinforcing upper strut tower plates. I ran these during an event with a loose front strut. My towers are completely fine. Would recommend.
4. Upper strut bearings.
Replace (pending what you're investing in for upper camber plates)
5. Ball joints.
Replace.
6. Front lower control arms
These can be replaced with stock (fine) and boxed (significantly stiffer "better" mostly for rally impacts tbh) or made full adjustable.
6a. There are 2 bushings here. I believe if using stock, you have no spherical option. So it's rubber or poly. This again depends on your driving style. Rubber will allow the transition from left to right to be smoother, but less connected. With rubber it is likely that your dynamic alignment will change more than with poly. With poly, you'll transfer tons of energy, but it can have adverse effects to the uninitiated. Most people would suggest poly on the front end. Doesn't make it right.
7. Tie rods inner and outer +boots
Inspect, replace. Keep old ones as spares if they're good. Or vice versa.
8. Front swaybar
Many options here. The KEY with swaybars is that you canNOT just stiffen and be "better" you need to BALANCE the front and the rear. Pure stiff in the front and you're understeering. Pure stiff in the rear and you're oversteering. 30k foot view. Use poly bushings for swaybar.
8a. Swaybar endlinks
Poly here also. You can also consider adjustable.
9. Upper GT braces
Get these?
10. Lower chassis braces
Get these?
11. Strut tower bar... only some work with gt braces.
That should take care of the front afaik.
I'll jump into the rear in a sec. Watson is yelling at me to do a thing.
I think realistically the car would be more geared for mostly street use. That being said, i still do plan to play around with it quite a bit. And quite a strong possibility that it will see the track some day.
Front -
1. Spring rate/coilovers, what would be your recommendation on this? I think that i will go with coilovers as you suggested, they've been on my radar for a while anyway. I dont think i need to get the JRZ RSone coilovers. I think the "DIY" ones offered by Kaplhenke would suffice. But one thing that has always deterred me from buying them is my lack of knowledge with the custom made ones. I am not sure what spring rate, if i should go with the shortened strut housings, and if i do, what struts will fit properly? And for the rears, it looks like its just an adjustable spring perch with the shock still in its stock location. As far as height, i do want to lower it quite a bit. Will probably end up doing fender flares or having to cut the inner wall and reweld.
2. Quick steer roll correction, will this effect the ride height? I will end up getting these regardless but have to ask for consideration.
3. Strut mount reinforcement plates, just bought a pair of the ones 15A makes. These should do or should i look at the adjustable strut mounts from Kaplhenke? Or the offset spherical strut mounts?
4. strut bearings, if sticking with 15A plates, then replace, but if going Kaplhenke they are included correct?
5. Front control arms, i have little knowledge of the boxing of the arms, but i have heard of them being done. IIRC a member here provides that service? With that said, should i bother getting new ones or just reuse the ones on there already?
6. Bushings, I tend to like to feel as much of the car and road as i can, so will probably go with poly in the FLCAs.
7. Tie rods, if getting the quick steer roll corrections, will this effect the way they are installed?
8. Sway bars, will probably end up using IPDs 25/25, have em on my 244Ti and love em.
9. GT braces/chassis braces/strut brace, already got em installed.
Rear -
1. With the package on Kaplhenke, the rears come with spring perches, but for coil over setup what would be entailed as far as modding?
2. Panhard, i was considering spherical over the poly, what would the differences be on those?
3. Bushings, front will go with poly, rears probably spherical.
4. Trailing arms boxing, i will probably get them boxed as well as the fronts.
5. Sway bar, will be matched with the front with 25mm
6. Fenders, will likely do flares, if not, cutting the inner wall and reweld.
7. Tires, this i know all too well, currently running blizzak studless and i hate them so much.