I just came back from Hawaii. We spent 3 days in Oahu & 8 on the Big Island. I would definitely bring the 17-40 for scenic/landscape & 50 1.4 for better lighting when the sun is down or indoors w/family. Plus, you don't want to just have one lens if something should happen to the 17-40.
I only used my 70-200 f/2.8 IS II like 5% of the time. If you don't mind having all that weight on you (& you'll be walking a lot, depeding on your itinerary (on the B.I. we were mainly in Hilo--Mauna Kea, Akaka Falls, Rainbow Falls; Valcano; & Kona), by all means bring it. But if I had to do it over again, I wouldn't have, especially if you are going in the summer & walking a lot.
The 17-40 & 50 1.4 would be a great combo and light enough. If you "have" to bring one more lens, I would say the 24-70 would do. Enjoy!