So in other words like I predicted, another dedicated spinner.
Err, only if you want the spinner to be on the x-axis and z-axis
both outside of mame. (You never made this clear.)
There are many conditions one spinner will be fine. I can't tell in your case because you only hint you want a "normal spinner" and a "scroll wheel spinner", but not which games or applications will use which of the two.
OTOH, there are many games in mame that can use two spinners, so there's nothing wrong with two spinners. And since you can remap in mame, it's fine if player 1's in one the X-axis and player 2's in on the Z-axis.
