does anybody have the actual com codes for KSAN or KSFO?
Airnav.com is the "unofficial" official source, as they pull their data from the official FAA source. "Unofficial" since Airnav.com does not want the liability and the costs associated therein if something goes awry with their posting of the data and a pilot dies from using their data.
You could also try the "official" source, which is the FAA's Airport/Facilities Directory and approach plate sites, here:http://www.naco.faa.gov/index.asp?xml=naco/online/d_afdhttp://www.naco.faa.gov/index.asp?xml=naco/online/d_tpp
but I would place money on the fact that both of these sites will concur with the data you see on Airnav.com
Do the airnav codes relate to the real ARTCC codes/ATC?
Yes, it does. However, if you are looking for specific approach and center boundaries and their corresponding frequencies, none of the sites I posted above offer them. As an active GA pilot, I don't know where these specific boundaries are published as they often are not common knowledge to us on the other side of the scope. Someone else here more in the know than I may have that.