in my head argenti can drink red wine like water, without as much as even getting tipsy, but the second he downs a shot, be it tequila, vodka or something else, he's in a COMA. down on the floor, hitting the Peter Griffin pose. heck, if he so much as drinks white wine he'll become an incoherent mess
only explanation for this is... something something... 𝓯𝓸𝓻 𝓘𝓭𝓻𝓲𝓵𝓪

as for boothill, the alcohol is much harder (impossible unless otherwise desired) to get to him since his blood system is not connected to his stomach in the necessary way, but regardless, i do think his drink of choice would be Whiskey or Jaeger (ew)... maybe some types of liquor as well – beer is always a great choice too
as for his tolerance, he would need to actively introduce alcohol into his bloodstream for it to take effect, where it would likely be efficiently cleared out, so the extent of its effect would depend directly on the quantity and concentration of how much he uses, but its duration would be relatively short. this can be both a blessing and a curse... still deciding between the two

PS: Boothill is a sentimental drunk, while Argenti is a sleepy drunk