Get a realtor there.

I rented with this group https://www.ocbeachfrontrentals.com/

Seeking recommendations for rental agencies with the largest amount rental listings. There are so many rentals in OC, literally when I'm there everything seems to be a rental but that does not appear to the case when I search Airbnb and Vrbo. Listings seem to be so fragmented among among many agencies. Is there a more centralized place to search for rentals?