Unless you are looking to have some extra time in HNL, you may want to consider FLL-LAX-KOA. G inventory will be much easier to access. Of course, you do miss out on the BE seat with this option.

Personally, I would use the miles. It sounds like you don't use miles too often and I can't think of a better time to use miles then assuring a better seat/service when you are going to be spending 10+ hours in the air.