When you are getting ready to bottle pull out 3 separate 4oz samples of beer add a different amount of bourbon to each one find one that suits your pallet and scale it up from there
i know how to weld but don't have any equipment so to do either would cost me about the same maybe even more building my own after the welder, stone saw , grinder , gas , filler wire and stock
But keep in mind if you ever use brettanomyces or another "bacteria" to only use them in glass fermentor or have a plastic bucket dedicated to using that bacteria.