I would plan on an extended visit to look around. If you are not local, I would secure a short-term stay somewhere first.

Rental books are no good for SFH, only apartments. I’m not sure what kind of service a realtor gets you. I would use various internet sites to get a feel, and actually scout some of these places on the ground.
Some sites: Craigslist, Signonsandiego (web version of the U-T), sdrentals.com (used to be really good, not so sure since they’ve been bought by westside rentals).

There are also various other small property management companies that specialize in managing SFRs for individual homeowners:
renthomes.com, utopiamanagement.com, sdppm.com, cal-prop.com
There may be more that specialize in the areas you are looking.