Hadn't noticed this post till just now lol. There's alot of differences in the diagrams when you look at the two bikes. The rotor on the zn doesn't have that center hub and the mounting bracketry looks different for starters. If you go forward with it you might want to make sure it'll mount up the same.
I wouldn't expect a noticeable increase in brake performance with just a slightly bigger pad. The brake is still a single piston design. If you stayed with your current calipers you could instead use the money to get pads with better material, have new braided steel lines fabricated, and make sure that your fluid is fresh and bled of any air. At that point there should be a noticeable improvement in brake performance
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