I struggle with the same thing when I visit friends in Spain. I know their tastes a bit now, so it's a little easier, but I try to stick with things that are made in the US. The first time I visited them (husband, wife and daughter), the little girl was 3 and I took her a variety of little hair accessories - bows, clips, etc. - in a little purse (she has always been a girlie girl). I took candy and Beer Nuts (made in my town and nowhere else in the world) for the adults, as well as a calendar of natural areas in Illinois. On my visit this year, I again took Beer Nuts for the husband (because he loves them), a small Yankee Candle in a votive candle holder for the wife, and the daughter, who just turned 12, got several kinds of sparkly nail polish and nail stickers, along with some fruit flavored lip glosses, all made in the US.
Regarding the bourbon - do you know if your friends like bourbon? Not everyone drinks alcohol. Are you planning to just take tiny bottles in your 3-1-1 bags, or put it in your checked bags?