Forget those that you're looking at on 4WO website.
For OEM: the best is style87 on the E53 body, style168 and style177 share 2nd spots. If you're on tight budget, there are replicas available.
However they are too commonly seen so I went aftermarket with HRE 648R.

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00 E39 DINAN S1 //M5 (82k miles)
06 E53 DINAN 4.8iS, born 2/18/2006 (126k miles) http://www.xoutpost.com/bmw-sav-foru...s-my-dslr.html
90 Straman Z32 TwinTurbo Convertible, (1 of 44 ever made) 5 speed, 444rwhp/451rwtq
01 360 Novitec Spider F1 (26k miles)