What year is your car ? I've put that same steering wheel on my car i had the old type like yours which is stage 1 and the M wheel was off a 99 Z i think pre 99 were all stage 1 anyway it was a straight swap
You can fit a 2 stage wheel to a single stage Z3 (pre 04/99 production) if you want a mangled face !
The two stage system has a low impact (1 small explosion) and high impact (1 small explosion followed by a delayed larger explosion) to deploy the airbag. No matter how you wire this to a single stage system the deployment of the airbag will be wrong and either not be strong enough or too strong and timed wrong.
You can fit a single stage airbag though to a two stage system by just bridging the high impact circuit. As the low impact circuit is fired in all cases the single stage airbag will deploy as designed.
To clear up the original question, both steering wheels pictured are E36 steering wheels and will fit the Z3 as a straight swap, there are numerous styles for the E36 have a look on RealOEM ande all E36 versions will fit the Z3. The difference on non E36 steering wheels is the slip ring.
I have both of these steering wheels in my garage plus a third in brand new napa and tri stitch fitted to the Zed. (All have been on the car at some point.
Got mine done a couple of years back by Jack and it's still looking in excellent condition (apart from two self inflicted scuffs). Takes a few months for the wheel to lose it's shiny greyish look, now mine looks like it's always been on the car...