Poly bushes will just make the ride harsher and put extra stress on supporting components. I know people often rave on about poly bushes, but if it’s a car used on the road, stick to the Lemforder original parts. Better for road use, and will last a very long time.
Put your reg into Eurocarparts, they will stock the front arm bushes.
Yeah, look at the great big void in the bush. Doesn't do much to locate the wishbone tightly.
Now look at the M3 bushing.
No air gap, and full thickness rubber. Nice and strong, holds the wishbone in place. This is why your M3 steering feels way better than the non-M model, and you would not say this is an unacceptable NVH increase in fact you just advocated OEM.