Nice write up.
Just some info you may want to check out regarding type 2 and 3 kits with the possibility of rear coilover option. Itīs a UK based operation called Nitron, they are known to be good in Europe. They have e46 and e92 M3 kits available.
Here a pic and link, maybe give them a call:
http://www.nitron.co.uk/nitron09/ind...cPath=2_60_327