I'm using up some bottles of Appalachian ginger beer, which is supposed to be a "Jamaican style" ginger beer and is fairly spicy. I think it might be too much for this cocktail, though, since the aged rum is going to be a bit more delicate than your typical base spirits used in most other ginger beer cocktails, e.g. mules... I'll have to try this one again with some Fever-Tree.
Since there's a lot of rum options one could use for this (and some have not worked so well according to the comments here): Appleton Estate 8 Reserve seems to handle the ginger beer well and does not get lost in the mix.
I made it with Thomas Henry. The result was a very drinkable, comparatively thick, intense drink. Appleton 12 Rare Casks was rather restrained and somewhat masked by the ginger beer. Havana Club 7 anos was incredibly good with coffee and caramel notes and a bit more sweetness. Go for a young rum, the indication here of 6-8 years is pretty good. And I recommend, really try it with the Havana Club 7 anos. Dave Brooms's recommends it for mixing with ginger beer in "Rum. The Manual" and he es right.
I must have missed something here. I just read your comment moments after making this with Havana Club 7 anos and Pierre Ferrand Dry Curacao. I think it might be the ginger beer I used, Fever Tree brand. The 'coffee and caramel notes' you mentioned weren't immediately apparent, but now I can subtly taste them. I guess I'll have to revisit this drink.
Not liking sweet cocktails, we upped the lime juice by 50%. Our ginger beer is a small-batch company and it is stronger in ginger, but has less sugar. Made a wonderful cocktail Nice strong ginger flavour and everything else is well balanced.
Very enjoyable. I combined Bacardi 8yr and Abuello Anejo when making two drinks. Nice combination pairing well with the citrus and ginger beer flavours!