Is there a reason you're looking at the M340i brakes? I'm sure it's possible, but I doubt they'd mount up without some adapters and I don't know if anyone makes them. I have the Freaky Parts(
https://freakyparts.co.uk) kit with the E9x M3 360mm front disc and RenaultSport Megane Brembo calipers on the front and Porsche 996 calipers and CSL rotors on the rear.