Thanks for all the help! My preference was certainly to fly MSP-HNL-KOA but from a first glance at NWA.com in order to secure a first class upgrade on that segment, it appears I need to book B class tickets which is more than I am willing to pay

So I'll have to look for less desirable options, as I'd prefer first class on a 757 to coach on a A330, but I'll take coach on an A330 over a coach on a 757 any day