part is not needed, unless you don't spend enough normally to meet your minimum spend to get the sign up bonus. But it is pretty easy to get flights and hotels to Hawaii paid for. I just returned from 1st class trip to Thailand with hotel/flights all on points. Mostly from sign up bonuses.
Will go to Hawaii later this year, Europe in the spring. Need to squeeze in another one this year because I can not spend the points fast enough. And I don't fly economy international.