A Circle Pac fare would probably fit your needs - you can get from west coast NthAm to GUM via KIX (xxx-KIX with UA or AC & KIX-GUM with NH).

With the circle pac, you can do your one required North Pac to GUM, back through KIX to SEL to SYD and then through the South Pac and on to HNL easily enough. If you have dates set in early enough, you might be able to get a cheap CO deal for a HNL-GUM-HNL return or use some CO points to get a reward. From HNL it's back to the mainland.

Not sure where that NZ not serving the South Pac year round comes from - they fly to PPT RAR NAN TBU APW year round. There may be some backtracking involved but the distances aren't all too great.