I swapped wheels on my Z1000, it is fairly easy if you get a similar hub size, Check your axle diameter then the diameter of the donor bike and make sure bearings are available. Machining up custom spacers sounds like a job your dad can tackle and the only other considerations are chain alignment and tire clearance on the swinging arm.
Take time to measure it all out before buying anything is my advice! I had to do a lot of research to find a suitable axle to use in my swap.
Bike is looking great, I would cut the cans down by a couple of inches to increase the mean look!!