I did a 98 front end on my 92 a while back, but now I am ready to have a speedometer back.
From a thread a while ago, you said to use a kawi wheel in to keep the stock mechanical speedometer. Which kawi bike?
zx7 or zx9 will work they have the same axle size as the gixxer also used the 320 kawa rotors so that I could keep the 6 piston brakes had to do a little mahineing of the speedo drive to center the wheel exactly also did a minor bit of machining again to exactly line up the center of the caliper on the discs. The ratio of the speedo drive is the same as the gixxer had to change the end of the kawa speedo cable at the speedo head end to take the ferule for the gixxer. Use pliers to bend the flair in put the gixxer ferule on the cable then bend the flaired end back out.