I see. California to HI is a five-hour ish piece of cake despite the distance. Weather is usually pretty amenable enroute, high level winds might be strong to about the mid-point. You might check ETP fuels out of CO airports, as it might be a factor in the 604, if their are strong jet level winds. No oceanic clearance needed. The tracks are fixed airways; the waypoints on each airway all begin in the same letter, there’s the “A”; “B”; “C”, etc. Usually no traffic problems enroute or at the Hawaiian airports. Honolulu is touristy, Kauai is beautiful, Maui is, too but more populated. HF or CPDLC all the way out. I’ve only used HF; ATC will send you over to SFO ARINC at oceanic entry. We had good luck with Castle and Cooke at PHNL and Air Service Hawaii at Maui. We were Marrioott fans.
If you go to Honolulu, Pearl Harbor in the morning; then North Shore in the afternoon. Haliewa for lunch, stop by Dilligham for a sailplane ride or watch the surfing at Waimea Bay.
West of Hawaii, I haven’t done in a number of years and then in planes with more range. Direct TYO is 3,400nm, so marginal in a 604 With a dry footprint. I don’t know if Midway is available for tech stop, but it’s perfect, if it is. Caution: Birds! Migrating Albatrosses, Nov-Jun
I’ve only flown corporate aircraft into Kansai—expensive, but superb handling. My company did use Nagoya and Chitose without problems except expense.
Your flight planner should be able to help with routing
http://www.airnav.com/airport/PMDY
GF