you can make a ZA50 CDI work. will have to install the flywheel without the woodruff key and set the flywheel position relative to the crankshaft. hopefully the stator+flywheel have a firing mark, but that can be found if not. Then, it would be exactly the same steps as installing an HPI ignition, there are Youtube videos for that.
the stock tomos ignition is likely better quality. (edited)