First off, coming from over 1500 hours in the CJ3, it will not make it 1900 nm with any wiggle room, zero. And ETOPS has nothing to do with 91, but the biggest issue is the the Oxygen bottle, not fuel for many planes that want to go to Hawaii. A Sovereign, will make it on gas, but if you have to drift down to below 10k or people will start to die. So you have to bring extra O2 bottles and use them while you are up there, and when you get with in a drift down range with the fuel you have you can take them off. That is how we did it. Also, from the SFO to Kona it is 2100 nm. For the price of the flight, they can buy every first class ticket on United.