OK...while coconut rum is a nice choice...I've found tequila is actually a nice alternative to anything in the rum family. I tend to steer away from silvers if I'm throwing in tequila for something like this. When I've done things like this at home...I've also experimented by throwing in splashes of Godiva White Choc. Liqueur, Frangelico, and Amaretto. I've thought about Midori and Curacao, but I haven't had either around to experiment. I have also swapped out the rum or tequilla with a bit of single malt scotch (whatever DH has around...most recently The Macallan- he called my experiment a crime against all liquor

) and Jameson, but neither really worked...although I still finished the whole thing
Edit...wait, there was a time when I did have some Curacao around...been a while, but it was tasty! Funny how the brain is going!