Recommendation, do a LOT of Pinside searches first. There is one vendor that is horrible at product and service who's name escapes me.
https://pinside.com/pinball/forum/topic/stencils
https://pinside.com/pinball/forum/topic/pinball-pimp-premium-cabinet-stencils-available-now
Pinball Pimp appears to be the front runner in the good vendor race..