99 Suzuki GSX600/750 (and probably 1000, but don't know for sure) forks are 41mm and a easy swap onto the GPz/KZ750's. Simple bearing swap and filing down the steering stem boss on the bottom of the top triple clamp. They are real close to the same length as the GPz750 forks, are fairly cheap, and give you better brakes, wider wheels, and 17" modern radial tires.
And the rear wheel off the GSX will fit the swingarm on the GPz750 (same size axle), and is 4.5" wide. Have to mill the sprocket mounting down for chain alignment though. I have the GSX750 front end mounted on my 80 KZ750E, just need to get the shock tabs (I'm using dual shocks) and brake stay mounting welded on the GPz750 swingarm I'm using.
