Just remember that the Buell/Harley mechanism requires a “pull” not a “push”. So you will need to find a pretty unique cylinder to do that, if you are trying to use the stock cable hole.
It’s probably easier to mod the adjusting cover to use attach a mechanism to.
I had the Magura setup on my bikes and the trick on the XB is to keep the hose away from the exhaust heat, while keeping it somewhat protected from external damage. The end result was that it was only marginally better than the stock setup after replacing the cable and lever.
Not saying it can’t be done, but I’d recommend checking out the Sportster forums to see if anyone found a slave cylinder to work. That will be the trick. The master should be pretty straightforward.