The only one available really is the JB4. The only other option is Hartge which costs triple and the rest requires you to remove the ecu to send to them (no thanks).
Current - 2013 N55 535xi Msport SAT
Retired - 2009 N54 335i Msport 6MT
Retired - 2000 M52TU 323i ASA Supercharged 5MT
More photos of my car here