IIRC, the Busa has a fairly lean stator output - 400-watts @ 5000 RPM.
If you don't have a Heat-Troller to be able to set your heated gear at a lower setting, you'll be making a pretty hefty 120-watt draw.
That said, I don't have a lot of Hayabusa-specific experience on how that bike handles this amount of load. But I have considerable experience on other bikes that do have significant electrical modifications.
The old Honda ST1100 was a carburetor bike with that a similarly lean stator capacity: 420-watts @ 5000 RPM. A 120-watt draw on that bike was definitely pushing it's performance envelope, if ran that way constantly.
Thus, on a fuel injected bike like the Hayabusa, 120-watts may *really* be pushing the issue if ran continuously. The 65-watt liner would likely have been a better choice for this platform.