Having lived in SAT a few years ago, I would suggest SAT-IAH-HNL, if you want a widebody aircraft (and UA F service is much better than US's). IAH is a very short flight from SAT and you still get the longer flight experience on a widebody aircraft.

A second option would be SAT-LAX-HNL or SAT-PHX-HNL -- at least you are going in the right direction.

I wouldn't even think of SAT-IAD-HNL. What if something happens (mx, ATC, etc.)? It could turn into a multi-day journey.