Just get a decent bottle of rum. No experienced rum drinker wants unknown glasses and most likely will prefer to drink from their own already selected glasses. I have many boxes of glasses given as gifts I never even opened because I don't consider them better than what I have I have estate glasses numbering hundreds but use half a dozen mostly 4 often, and it would be very hard to pull me from my usual glasses. I don't know their collection but any decent rum even a 25 dollar bottle will be taken much happier. I'm sure there is something even in lower ranges they have not bought.