There are helicopter tours available on every island. They are all the biggest, best , with the best helicopters and most experienced pilots (at least if you believe their advertising). It would seem to me that there would be three tours I would consider.
1) Hilo- taking a flight over the active volcano 2) Kuai- taking a flight along the Napali coast (like Jurrasic Park) and into Waimea Canyon 3) Maui - taking a flight over Haleakala Volcano .
Gram is deathly afraid of helicopters so it is not something we have looked into in depth. There are a number of companies on each island and they are very competitive.
It is hard to get a reservation when there is a cruise ship in port, you might want to look into booking online. The one compnay that advertises the most is Blue Hawaiin.
Try a google search for helicopter tours hawaii. I'm sure you'll get all the information you need. Also check out guide books like Frommer's , Fodor's or Maui Revealed for their
recommendations. Worth the research as the trips are not cheap.