Here i offer a variation of the 312-294mm Brake System for the E30 with 4x100 under using the 135i caliper with 6 pistons in front.
This brake system ist build for 17 inch wheels.
Rear you can use the 294x19mm Brake System with BMW 1-piston caliper (E34 540i-E32 750i, M3 E36) or 4-piston caliper (PORSCHE 986-996).
... to the shop offers ...
Links
Description 312x25mm Conversion with 135i Caliper E30 Front
Description 294x19mm Conversion with E34 540i Caliper E30 rear
Description 294x19mm Conversion with Porsche 986 Caliper E30 rear