I am gold with United, so perhaps stick to that, but fares are very good. WPB it is. I definitely like the large staff more. What are your recommendations for dive boat operators and tank rental places for shore diving and a good base to live in?
Many of us post dive reports for Palm Beach County quite frequently in the Florida forum. For recommended charters, see the following general dive report threads along with many individual threads covering locations in the county:
Palm Beach: Palm Beach Dive Thread
Jupiter: Jupiter Dive Thread
One additional area to consider is Boynton Beach. See @scubadada's excellent trip reports for his many dives there. Many of us also dive there, but his posts are the most helpful in terms of researching options.
As far as dive shops for rental equipment for BHB, there are two primary ones that are close to BHB. Pura Vida, just east of the park on Singer Island, and Force-E Riviera Beach, just west of the park just west of Blue Heron Bridge.
As far as good home base locations to stay, focus on the northern portion of the county from Palm Beach Gardens on north. That would be my recommendation. Lots of hotels, and many inland should be affordable in October, as well as AirBNB options.