The best way is use your VIN and check in www.realoem.com like what TheTaj said Please note that not all models carries the same disc rotor size. For example a 520i/523i has a smaller disc compared to 530i and in the US, 540i and above uses the same disc rotor as a UK spec 530i.
Here , the e38 750 suit for you ,334mm x 32 rotor with caliper , but needed custom make the bracket .Very good braking power .brake pad bite rotor surface going for 70mm.