Also, we took a shuttle up to the sunrise ceremony and biked down. We are both late 40's and semi-fit (daily long walks, but nothing particularly vigorous) and we did fine. You'd need to get up earlier.
We took a Hana Tour that returned via the south part of the island. At time the scenery was kind of monotonous, but it was an interesting contrast with the rainforest of the SE. The last stop is a winery. The drawback is that it takes all day. Well, and no helicopter.