I bought APR springs, which are lower than the claim .5 to .75, but lowered car about 1". I'm using stock struts and shocks until they die, then I'll go Koni. 26mm RSB. Eurosport camber kit. I was able to get -2.4, but requires loosening strut bearing bolts and the three bolts securing ball joint to LCA, and using all available play. Moog rear end links. AP OTS stg 1 91 oct tune, but I run 93 oct. I do this because I'm trying prolong the life of the clutch. REe16 17 x 8.5 with 245/40 17 RE71R's. I didn't go 255 because I had a new set of 245 from my GS build, but will go 255 next time.
I also added Brembo 4 pots, which aren't needed, but since I track too, I was going for cheaper pads, more choices, and ease of swapping.
The car is so much fun to drive now and when I run my street tires, it's as well behaved as it was stock, though my street tires are 225/45 17 FK510's' so they help a lot with that. I threw them on my old GS Runlite wheels and sold the 18" Pretorias and stock tires.