We have a plug-in ECU for the M50 as of 2014, but gained traction and refinement in 2015.
https://shop.vems.hu/catalog/vems-motronic88-p-187.html (Entire World)
or
https://www.vems.com/engine-management/m50-pnp.html (US Customers)
The BMW M50 family is popular in the e34 and e36 chassis cars from 1992-1995. The S50 in the US is compatible with the M50 plug-in ECU. The S50 in Europe is a different engine, but we also support that.
If you would like to wire the ECU into the car, for a motorsport application or similar where the full BMW harness is not needed or wanted, you can specify an ECU with 8 Ignition Drivers, EGT if desired, VR/VR for non-vanos (m50b25) or VR/Hall for Vanos (m50tub25), 30V flyback, 400kpa (or your preference) MAP sensor, 2 knock input channels. Also don't forget the associated connectors (ec18, ec36, lsu4.2 or lsu4.9) and fast open element intake temperature sensor (stock is slow response sensor because the car was MAF stock)