Airbag is the problem with the M-steering wheels; they are at least $600. Finding the correct one used is very difficult to due the fact that few of our cars were issued with them and shipping an explosive item can be an issue.
I took a serious look at doing this about six months ago. The airbag and all the original option steering wheels are still available through the BMW system but the basic M- steering wheel with slip ring and covers (about $350.00 IIRC) and the appropriate airbag total >$1000. My conclusion, too expensive if you want to do it right, ie - functional airbag no annoying lights in the cluster. | 
Linear Mode
