You should be fine. They both run 12V systems, and the reg/rect will provide that.
The regulator trims off the spikes coming from the power source (alternator). So, anything above 14.4V will be attenuated. The rectifier turns alternating current (supplied from the alternator - hence the name "alternator") into direct current.
The only thing you need to check is if the alternator and rectifier can handle the load coming from the alternator. Considering how weak the alternators on our bikes are, I imagine the XS system is more than sufficient.
I have no idea what the wiring on the XS looks like though, so you are on your own with that part.
Camelman