So I know I need the valve clearances set right, but asking the only sportbike/big bike Yamaha dealer (RevZone) they said it will take *more than two months

Could shims from other brand of bike (say Honda or Kawasaki) would be usable, or from desperation, order shims from China? Or wait for the 2+ months and discover I need more shims to get the clearances right? Would hate sanding them down, but if it has to happen then it must. Any thoughts?