As a bourbon fan from Kentucky, I find that the 12 yr old Appleton's rum is a great substitute. This is not the regular Appleton's most bars use for rum drinks. It is aged in barrels just like Kentucky bourbon and available
most places. For some reason, I think that there are fewer hangovers with the Appleton's. At home I'm a Maker's Mark fan.

Respect,
Col. Andy & "Wildcat" Pam