HNL Alternate
There are of course a good number of airports that can be considered for alternates. Ie. OGG Kahalui (sp) Airport in Mau... not to forget there is Kona as well as the Island of Kuaii.
For large twin jet operations flying ETOPS to HNL fuel is never a problem for getting to anyone of those airports as alternates as once the fly past the ETP (Equal Time Point) they now have more fuel than required for an alternate in Hawaii. As for holding the mainland as an alternate.... well that is what ETOPS aircraft do from the departure point to the ETP. Thence it is normal weather requirements at planned destination and planned alternate airport.
Hope this answers you question without creating too many more.
ea306