Finally, the other item I forgot to include in my runthrough of what you need you consider as part of your M5x swap is - amongst your certing, suspension refresh, and brakes - the 5 stud swap. If you want to know how it's done, don't ask - google. A specific form of e36 front control arms, some knuckles, the rear from one of the Z3's or a Ti (I forget which), and then of course the right rotors, calipers, pads etc. You'll find more -ve camber, and a big selection of wheels... join the long queues of e30 conversion owners looking for a diminishing supply of the same 16 and 17 inch 5 stud wheels.
Have you bought a car yet?