i would try either nyc or hong kong. since it's probably impractical to go to either place unless you plan to be there anyways, i would contact nyc seller john buckley or geouge at tempus fugit, or in hong kong try any one of many members here. i think steve p could also point you in the right direction as he is really in tune with the gold daydates and has contacts in his area too.
as another option, you could pick up a yellow gold genuine president bracelet and have it professionally plated in white gold. not factory original but certainly close and all rolex.
one thing for sure, whatever band option you choose, your watch is a stunner!