When we were on Maui the couple with us did the bike ride up the mountain (can't remember the name right now and probably couldn't spell it even if I could remember it). Anyhow, they said that was an incredible thing to do.
You could do the very high priced helicopter tours. Let us know how it is if you do it.
We did the luau on Maui. My goodness, our kids were 2 and kindergarten when we went, so it was a long, long time ago
Wish I could tell you the name of it because it was really nice. Right on the beach so you could watch the sunset. Great show. Good food (except the poi, but you still must try it)
It won't matter what you do there, it will be fantastic. I wish the Lord would call us to serve Him in Hawaii. To that, we would say "Yes, Lord, yes!" right away!!