Curacao is a bigger version of Bonaire with very similar diving, Should be easier/cheaper for you to get there,
Almost all the beaches are also dive sites with on-site operators. They also have several drive-up rebtal locations across the island. And day boat trips toKlein Curacao.
Turks/Caicos is as expensive as Cayman, All deep walldiving but virtually no shore dives.
Rocio Del Mar does the Sea of Cortez Midriff Islands (NOT Socorros) during the summer months, Lots of sealife, sharks, occassional whales (no diving) and they visit a sealiob rookery. Nice thing about that trip is you fly into Phoenix and take their shuttle to the boat in Puero Penasco - about a 4-6 hr ride depending on customs, It may be warm as late as October
Hawaii is also very good diving. Not the soft corals you are used to but I've seen acres of hard coral off some islands, Also the Lava tubes extend into the water - always something moving on the ceiling - often octos. I've seen scools of butterflies and tangs numbering in the thousands off Lanai. And lots of reef sharks, Plus an occasional Manta flies by, My buddy dove with 100's of Spinner Dolphins off the big island and you might see a Monk Seal off Kauai.
It's also easy to fly between islands in a week or more. From Maui you can boat dive to Molokini Crater, Lanai, Possibly seee Hammerheads off Molokai plus there's about 15 shore dives, Less on the Big Island or Kauai, I don't go to Oahu,
Long flight for you though but out of LAX/SFO you get there early afternoon with the time change.
Maybe look at Roatan also, it can be very cheap once there. Flights seem higher but food/lodging is hostels on up. Dives are cheap 10/$350 or so. All boat diving except a couple known resorts have a house reef. Lot;s of Bugs...