TC Kline would be my suggestion. I'm running the Single Adjustable true match kit from TC kline with 550 F and 700 R spring rates. Previously had 450 all around and looking to go to 600 F.
You're more then welcome to drop by any time and we'll go for a spin.
I also have e30 M3 front control arms and offset bushings, TC/K front camber/caster plates and rear eccentric offset bushings for toe/camber adjustment. I have a 28mm H&R front sway bar and removed the rear one. Using Ireland Engineering rear subframe bushings (You have to get those) and the Randy Forbes rear re-enforcement kit with an e36 dual diff cover.