My husband and I went to Kauai last May for our honeymoon. We hiked Na'Pali but not past the area where a permit is required so I can't help with services. We did the same Hanakopei trail already mentioned to the waterfall. It was awesome. We also did said mentioned 17 mi kayak of the coast. It's a LOT of paddling but excellent scenery!! Have a great trip, we had a blast.

PS. Check out the pineapple coconut ice cream at the shave ice stand in Hanalai. We ate it every day. YUM! The Dolphin restaurant market has nice sushi and poke to go for a sunset beach picnic too.