Late post but I have the German EHC and zero electrical problems. The factory wiring is actually very good, just need the EHC but if you want to spend money/time I'm sure the RIP kit is very good.
I have not changed any other parts out including the charging system, rotor, stator, or voltage regulator and it doesn't seem to be a problem (knock on wood). I would however ensure your connector pins are all straight and onbroken as per Mickmorris's post.