Here at 77, we have built quite a few custom mopeds over the years. One constant fight is with which controls to use. At least it was.
This is our house setup for controls.
We use the longpull throttle, universal leverset, and then the universal double ended throttle cable. It mates perfectly with the Mikuni 24mm Carb.
You choose your own handlebars. But this setup will get you close.