I'm hearing a lot of talk about saving money for a money is no object thread.
Drop out the front and rear subframes and retrofit the frames from a 1M. It's not too much of a difference from all M3 parts in the front. But in the rear it completely changes the suspension geometry.
Do that - and ER kit up front + LSD and you'd be pretty set
Motorsport Photographer, PM for Pricing on Car Shoots - mattkalish.com