I just moved to M3 suspension all around (from the Sport suspension).
The M front sway bar bolts to the struts, so it will not work on its own. You should also look at M3 control arms - more money that stock, but sharpens turn-in.
If you are on a budget, and want a definite improvement, I've got my old sport suspension for sale...
E36 Sport Suspension For Sale
I bought the car new, and test drove both the sport and stock suspensions. The sport upgrade blew me away - no lean in the corners, visibly lower. I had to have it.
Go for it!