The most powerfull brake solution on this website use the 6 Piston calipers from PORSCHE Cayenne (955) together with the M3 E46 CSL discs 345x28mm. This kit needs 18 inch wheels.
parts in front: Caliper PORSCHE 955, Audi Q7 and VW Touareg, BREMBO Part Number 20.8432.07 und 08 (17ZL/17ZR)
Brake discs M3 E46 CSL 345x28mm BMW part nr. 34 11 282 445 und 446
On rear we use the 294x19mm Brake solution with PORSCHE 986 rear calipers.
On the rear the 5x120 conversion can realize easy with E36 323ti compact hubs.
parts in rear: caliper Porsche 986-987-996 HA Teile Nr. 996.352.421 und 422
brake discs Z4 E85 2.5si 294x19mm BMW Teilenummer 34 21 6 794 303 (compact hubs)
or
brake discs E46 328i 294x19mm BMW Teilenummer 34 21 1 165 563 (Z4 hubs)
... to the shop offers ...AnleitungenDesciption 345x28mm brakekit incl. 5x120 Conversion on E30 front with 955 calipersDescpription 294x19mm brakekit on E30 rear with Porsche 986 calipersDescription 5x120 conversion with Z4 Hubs on E30 rear (www.e30.de)
Description 5x120 conversion with E36 Compact hubs on E30 rear (www.e30.de) 
