No don't buy both. You can make the tool into the Kawasaki tool by disassembling it and using the hook shaped side as a pry tool.

It is much better for getting at the rear shims, that's how I did it.



I think sanding the shims would be a lot of work for little benefit. I'd worry about getting a consistent thickness. If you have a mill, that would be the tool to use. They probably sell after market shims with more thicknesses.

Keep in mind that since you know the shim thickness now, you wont have to remove it to measure it next time it needs replacing. The first service will be the worst, and it get easier as you know the engine.