Found out one of my friends did this to his m42 5 years ago and is still going strong.
He used bosch coils used on the latest e46, e90 and minis.
Here are the part numbers from real oem 
https://www.realoem.com/bmw/enUS/showparts?id=BL93-USA-05-2006-E46-BMW-M3&diagId=12_1104I got the pinouts from newtis.info
The plug pn is 12527519996 and the pinout is :

   1   Trigger      
   2   Ground      
   3   12v
My car uses a round plug with 7 pins pn. 12521718125.
only 6 pins are used and the pinout for the plug is :
      Pin assignment, primary connection      
Pin 1 = terminal 1 of ignition coil 1      
Pin 2 = 12v
Pin 3 = Ground
Pin 4 = not allocated      
Pin 5 = terminal 1 of ignition coil 4      
Pin 6 = terminal 1 of ignition coil 2      
Pin 7 = terminal 1 of ignition coil 3
Hope this helps anyone trying to upgrade the coils on their m42s